Thrace

The Thracian, earlier known as the Odrysian Kingdom was a Thracian kingdom that existed from the early 5th century BCE, until 189 BCE. It consisted mainly of present-day Bulgaria and parts of Southeastern Romania (Northern Dobruja), Northern Greece and European Turkey. Dominated by the eponymous Odrysian people, it was the largest and most powerful Thracian realm and the first larger political entity of the eastern Balkans. Before the foundation of Seuthopolis in the late 4th century, it had no fixed capital.

The Odrysian kingdom was founded by king Teres I, exploiting the collapse of the Persian presence in Europe due to the failed invasion of Greece in 480-79 BCE. Teres and his son Sitalces pursued a policy of expansion, making the kingdom one of the most powerful of its time. Throughout much of its early history, it remained an ally of Athens and even joined the Peloponnesian War on its side. By 400 BCE, the state showed first signs of fatigue, although the skilled Cotys I initiated a brief renaissance that lasted until his murder in 360 BCE.

Afterwards the kingdom disintegrated: southern and central Thrace were divided among three Odrysian kings, while the northeast came under the dominion of the kingdom of the Getae. The three Odrysian kingdoms were eventually conquered by the rising kingdom of Macedon under Philip II in 340 BCE. A much smaller Odrysian state was revived in around 330 BCE by Seuthes III, who founded a new capital named Seuthopolis that functioned until the second quarter of the 3rd century BCE. The Odrysian heartland was eventually annexed by the Second Macedonian Empire in 189 BCE, during the Thracian War (192-189 BCE).

After the collapse of the Pontic Empire in 235 CE, the Sasanians invaded Thrace, establishing a client state, eager to restore the boundaries of the Achaemenid Empire. However, in 238 CE, the Goths raided and invaded Thrace and established their own kingdom, waging wars with the Persians for decades to come.

After the retreat of the Huns, from Thrace, in 458, the Thracians managed to gain independence, establishing the Kingdom of Thrace. However, Thrace was in ruins; destroyed, plundered and devastated, like most of Eastern Europe. Even the Sassanids weren't eager to conquer Thrace, as there was almost nothing left anymore, and the Persians themselves had to recover from the Huns, and had to rebuild Mithripolis.

Thrace and its early history
Since the ancient Thracians lacked an indigenous writing tradition, the most important sources for the reconstruction of their history are archaeological remains, coins as well as accounts of ancient Greek historians. Said historians considered the Thracians to be a numerous people and their country, Thrace, to be of barely comprehensible size, so large that Andron of Halicarnassus (4th century BCE) thought of it as a continent of its own. While the boundaries of Thrace fluctuated throughout history, Thrace can be divided in a northern and a southern half, which were also culturally different. The border between the two halves has been identified as the Haemus Mountains or the Danube slightly further north. Southern Thrace covered the fertile valley between the Haemus and the Rhodopes, the Strandzha and the shores of the Propontis and the Aegean and Black Seas. The western boundary was marked by the Strymon and the upper Morava. Northern Thrace was defined by the Danube, the Carpathians and the adjacent western tip of the Pontic–Caspian steppe, thus enclosing parts of the territory now comprised of modern Romania, Moldavia, Serbia and Ukraine. Thrace also extended into what is now northwestern Turkey, both west and east (Bithynia, Mysia) of the Propontis.

Thracians already featured in the epics of Homer, which were settled in the 2nd millennium BCE. Occasional references to them appear in the following centuries, although it was not until the 5th century BCE when Greek literature developed an interest in discussing non-Greeks more extensively. In the 7th and 6th centuries BCE, much of the Thracian coast was settled by Greek colonists who founded numerous towns, like Thasos, Byzantion or Odessos. The political history of the Thracian tribes of this age is virtually unknown, although it is recorded that in the late 6th century BCE, Athenian settlers interacted with a "king of Thrace" (and possible predecessor of the Odrysian kings?) residing north of the Chersonese peninsula. The absence of imported artefacts confirms that inland Thrace north of the Rhodopes remained largely isolated from the Aegean trade until the late 6th century BCE.

Persian Thrace
In around 513 BCE, an army of the mighty Persian dynasty of the Achaemenids crossed the Bosphorus, after already having subdued the Thracians of Bithynia thirty years earlier. King Darius I's goal was a punitive expedition against the Scythians at the northern shores of the Black Sea. Most eastern Thracian tribes submitted peacefully, except of the Getai, who were defeated. More expeditions under the generals Megabazus and Mardonius as well as king Xerxes I followed, even though they only managed to secure the Aeagean coast.

It seems most likey that the Achaemenids did not establish a satrapy (provincial administration) in Thrace, even though the historian Herodotus claimed that the subdued regions had to pay taxes. As a matter of fact, there is no evidence for important administrative centers. Instead, Persian authority was merely exercised through a couple of garrisoned forts, most importantly those of Doriskos and Eion. Hence, the vast majority of Thrace remained unaffected by the Persian presence. After the failed invasion of Greece in 480-79 BCE, the Persian foothold in Europe collapsed. By around 450 BCE, Persian authority in Europe, including Thrace, had vanished entirely.

Early tribal kingdom
Although the Persian presence in Thrace was short-lived, it probably stimulated trade and first state formations among the Thracians. Mintings of Thracian coins started around 500 BCE, and may be an indicator for a variety of early tribal kingdoms. It has been suggested that the Odrysian kingdom might have had its origins in this period, even though the name of the Odrysians is notably absent from the numismatic evidence. The Odrysians eventually stepped into the light of history in the aftermath of the Persian failure in Greece, when they were mentioned by Herodotus, but without any further details. The Odrysians had their core territory in the valleys of the Hebros river and its tributaries Tonzos and Arda. Like other Thracian polities, the Odrysian tribal kingdom attempted to fill the vacuum left by the Persian retreat.

Expansion under Teres I
The first known Odrysian king was the expansionist Teres I, who is claimed by Thucydides to have been the first Odrysian king altogether. Writing in the late 5th century BCE, he wrote that Teres "was the first powerful king of the Odrysae" and that he "was the first founder of the great Odrysian empire, which he extended over a large part of Thrace, although many of the Thracian tribes are still independent." Said independent tribes consisted of Thracians living along parts of the Aegean coast and in parts of the Rhodope mountains and as well as the powerful Triballi around the Haemus.

Teres most likely came to dominate central Thrace soon after 480 BCE. Building his realm on a privileged warrior aristocracy, he and his son Sitalces expanded the realm from the Danube in the north to the outskirts of Abdera at the Aegean Sea. He also expanded to eastern Thrace, although he suffered a setback at the hands of the Thynoi. In the northeast, he cemented the position of his realm by allying himself with the kingdom of Scythia under king Ariapeithes, who married Teres' daughter. In conclusion, the Odrysians were the first to superseed the Thracian tribal system and establish a large state in the eastern Balkans.

Around the middle of the 5th century BCE, when Sitalces had not yet succeeded his father, the Odrysians intervened in a Scythian civil war, seemingly on the side of the dethroned king Scylas against Octamasadas, who was a son of Ariapeithes and Teres' sister. When the two armies met at the Danube, however, Sitalces simply agreed to hand over Scylas (who was killed on the spot) for an unnamed brother of his who resided among the Scythians. Another important event may have happened further east, in the Bosporan Kingdom, when a Thracian named Spartokos seized power in around 438 BCE. It is not unlikely that he was of Odrysian descent and that his takeover was instigated by the Odrysian royal house, although this must remain speculation.

The early Odrysian elite in archaeology
Archaeological evidence confirms that by the middle of the 5th century BCE, a new and powerful elite had emerged that accumulated a wealth of precious artifacts of both local and regional origin. Burial practices were changing after the Persian withdrawal and a new type of elite burial emerged in central Thrace in the form of tombs with ashlar masonry, sometimes with stone sarcophagi. The tomb of Rouets from the late 5th century even contained traces of wall paintings. The earliest of these new elite tombs can be found in the necropolis of Duvanli, with the oldest tombs dating to the mid-5th century. Their inventory is exceptional not only by contemporary Thracian, but even Mediterranean standards. According to the archaeologist Tonkova they contained "splendid sets of head and body ornaments, consisting of numerous hoop or boat-shaped earrings, pendants for earrings, a necklace, a torque, bracelets, finger-rings, chains with pendants and fibulae, and pectorals." Most Thracian elite tombs have been identified as warrior burials, as they contained weapons and gold pectorals. Two burials from Svetitsa (second half of the 5th century BCE) and Dalakova (early 4th century BCE) also contained finely crafted and rather impressive gold funeral masks.

Sitalces and his alliance with Athens
Teres, who is claimed to have lived 92 years, had died by the outbreak of the Peloponnesian war in 431 BCE. His successor was his son Sitacles, whose reign is mostly known thanks to the account of Thucydides. Before the war he is known to have campaigned against the Paeonians in the west, subjugating some of the tribes living along the upper reaches of the Strymon. Now, his influence extended over much of Bulgaria, Greek and Turkish Thrace and also parts of southeastern Romania: from the Styrmon and Iskar rivers in the west to the Black Sea and the Propontis in the east as well as the Haemus and the mouth of the Danube (which was ruled by the tributary Getae) in the north. According to Thucydides, the Odrysian state was "very powerful, and in revenue and general prosperity exceeded all the nations of Europe which lie between the Ionian Sea and the Euxine [Black Sea]."

In the south, much of coastal Thrace had passed under the rule of Athens, making them direct neighbours of the Odrysians. The Athenians had already taken some interest in the Thracian interior before 431 BCE, but it was in said year when they concluded an alliance with Sitalces against Perdiccas II of Macedon in the west. This pact was cemented by a dynastic marriage, as Sitalces would marry the sister of the Athenian ambassador, Nymphodoros of Abdera. Sitalces' son Sadokos was sent to Athens and was granted the Athenian citizenship. Sitalces, apparently an experienced leader with political acumen, would prove his commitment to the alliance in the next year, when he arrested a Peloponnesian embassy that tried to persuade him to join the Spartan side and handed it over to Athens.

At the turn of the year 428 BCE, Sitalces raised a massive, multi-ethnic army to march against Macedon and insurgents on the Chalkidiki peninsula. His army consisted of a variety of Thracians (some, like those of the Rhodopes, were independent, but joined nonetheless), Getae and some Paeonians. While Sitalces managed to subjugate some of the Thracian tribes of the lower Styrmon his invasion of eastern Macedon and the Chalkidiki was less successful, as his opponents avoided open combat and simply hid behind their walls. The Odrysian army had not the means to storm them, plus winter was approaching and food supplies were running out. Furthermore, the Athenian force that was promised to them never arrived, perhaps because Athens feared the might of the unleashed Thracian kingdom. After failed negotiations with Perdiccas II Sitalces retreated back home. Thus, after only 30 days, the Odrysian invasion had come to an end.

Seuthes I
Sitalces was succeeded in 424 BCE, by his nephew Seuthes I after the former was killed while campaigning against the Triballi, who resided north of the western Haemus. Throughout his reign, the Odrysians did not intervene in coastal Thrace, which had now become a contested battlefield between Athens and Sparta. Athens for its part began to make heavy use of Thracian mercenaries acting as light skirmishers, the peltasts. Due to their success the Greeks soon began to raise peltast units of their own. Still, the Athenians eventually lost the Peleponnesian war and, for a few years at least, much of their influence in the northern Aegean. Seuthes I was eventually succeeded by Amadocus I, also known as Medokos, in around 410 or 405 BCE.

The civil wars between Amadocus I and Seuthes II
By the turn of the 4th century the Odrysian kingdom showed its tendency towards fragmentation. Two rulers are known by 405: Amadocus I and Seuthes II. The historian Diodorus Siculus even called both of them "kings of the Thracians", although this is most likely a misunderstanding: by 405 Seuthes II still considered Amadocus I as his suzerein. Amadocus was the son of the previous king Seuthes I, while Seuthes II was the son of a Thracian chieftain named Maisades. Maisades was a descendant of king Teres, making Seuthes II and Amadocus I distant relatives. There was also an autonomous Odrysian prince in the western hinterlands of Byzantium named Teres.

Initially raised at the court of Amadocus, Seuthes was sent to eastern Thrace several years before 405 BCE. By 405 BCE he had managed to consolidate his position over a realm stretching from Apollonia Pontica over the Strandzha to parts of the northern Propontis coast. In 400 BCE, he hired Greek mercenaries under Xenophon to expand his dominion at the cost of Teres and other rebels, forcing them to reacknowledge the authority of Amadocus. Due to lacking funds they left his service already after two months. Seuthes II eventually rose against Amadocus, although little is known about this insurrection. In 389 BCE, the Athenian general Thrasybulus mediated between the two parties, resulting in Seuthes II, whom Xenophon called "ruler of the coast region", recognizing Amadocus' authority again.

Amadocus, who had defied Seuthes' insurrection probably due to his own popularity, died soon after 389 BCE. His successor was Hebryzelmis, about whom very little is known, but who, like Amadocus, sought the good will of Athens. Seuthes II on the other hand allied with Sparta. An Athenian inscription from the year 386/5 BCE, confirms that Hebryzelmis sent a delegation to Athens to legitimize his rule and/or gain an ally against Seuthes. However, the Athenians had little interest in another war in the region and thus limited themselves to kind words. Meanwhile, Seuthes had risen yet again against the crown. This second war went badly, as he seemingly lost all of his domains before reconquering them thanks to a mercenary army led by Iphicrates. Iphicrates subsequently married the daughter of Seuthes' son, Cotys I.

Renaissance under Cotys I
Cotys I succeeded Seuthes II in 383 BCE. The historian Michael Zahrnt described Cotys as "the right man to strengthen the run-down Odrysian realm, vigorous, and an artful diplomat [...]." Indeed, it was under him that the kingdom reached its greatest might and became a considerable political factor in the nascent Hellenistic world. He was also the only Odrysian king whose character was excessively discussed by ancient scholars, although primarily in a rather unfavourable way. While virtually nothing is known about the early years of his rule it is clear that he, together with his son-in-law Iphicrates, managed to conquer the domains of the deceased Hebryzelmis, thus uniting the Odrysian realm under his rule. In 375 BCE he faced an invasion of the Triballi, who devastated the western parts of the realm while marching towards Abdera at the coast.

Cotys eventually set his eyes on the strategic Chersonese and the Hellespont, challenging the Athenian hegemony in the region. The Athenians were more than ready to fight for the control of the Hellespont, as it was vital for Athens' grain supply from the northern Black Sea region. An early invasion in 367 BCE failed, but in 363/2 BCE Cotys was more successful and repeatedly defeated several Athenian generals. Thus, the Chersonese and the Hellespont had come under direct Odrysian rule. This achievement, however, proved shortlived: much to Athens relief, Cotys I was eventually murdered in 360/59 BCE.

The three kingdoms
The death of Cotys, almost contemporary to the coronation of the talented Philip II of Macedon, marked the beginning of the kingdom's downfall. The Odrysian state was divided among three competing kings: Cersebleptes, the son of Cotys, ruled the eastern parts beyond the lower Hebros and Tonzos; Amadocus II, perhaps a son of Amadocus I, ruled central Thrace between Maroneia and the Meritsa; Berisades controlled the western part from Maroneia in the east to the Styrmon in the west.

Cersebleptes was the most ambitious of the three. He continued his father's war against Athens for the Chersonese, while also striving to reunite the Odrysian kingdom. His attempts proved futile, for Amadocus II and Berisades, who received support from Athens, resisted his attacks. In 357 BCE, he was forced to accept a peace treaty that sealed the division of the Odrysian state. An inscription from Athens describes said treaty. First, Cersebleptes had to cease his hostilities in the Cheresonese. Second, all three kings and Athens agreed to share their tributes received from the Greek colonies along the Aegean and the Hellespont. Third, the kings promised to enter an alliance with Athens and both sides had to provide each other with military support if tributary Greek colonies revolted. Cersebleptes, however, soon quit that treaty and continued his war in the Chersonese.

Conquest by Philip II
As early as 359 BCE, the year of his coronation, Philip II of Macedon I contacted a "Thracian king" to persuade him to not harbour a Macedonian pretender to the thone. This king is probably to be identified with the western Odrysian king Berisades. A year later he unified Macedon and subjugated the Paeonians to the northeast. In these early years he did not bother much with Thrace yet, as he regarded the infighting Odrysian kingdoms as no threat for his rule. A first push into the kingdom of Berisades and his successor Cetriporis occurred in 357/6, when he conquered Amphipolis and Crenides. The latter was made into a garrison town called Philippi that was to serve as a launch pad for future invasions into the interior. Cetriporis allied himself with the kings of Paeonia and Illyria, but Philip II defeated them one by one. Cetriporis was allowed to keep his kingdom, at least for a few more years.

Cersebleptes continued his attempts to unite the Odrysian kingdoms: in 353/4 BCE he and Philip discussed the invasion of the kingdom of Amadocus II and the Athenian domains in Thrace, while around a year later he marched against the kingdom of Cetriporis. Meanwhile, Athens feared a possible alliance between Philip and Cersebleptes and decided to make an example by conquering the town of Sestos and eradicating its population. Intimidated, Cersebleptes renounced his claims on much of the Chersonese and allied with Athens. This was unacceptable for Philip, who allied with Amadocus II and marched against Cersebleptes. After besieging him in his residence in Heraion Teichos in 351 BCE, he forced the Thracian king to surrender and took his son as a hostage. Around this time, Philip also abolished Cetriporis' kingdom and deposed Amadocus II in favour of Teres II.

After these events, the Thracian front remained peaceful until 347 BCE or early 346 BCE, when the Athenians again attempted to strengthen their presence in Thrace, which they probably did at the request of Cersebleptes. Macedon expelled the Athenian garrisons and defeated the Odrysians, preventing yet again a Thraco-Athenian alliance against him. As a result of this campaign Philip also put the Aeagean coast as far east as Acontisma (not the banks of the Nestos river as often assumed) under direct Macedonian administration.

A few years later Cersebleptes allied with Teres II and invaded the Chersonese, which was now under Macedon's protection. After asking the Persian king Artaxerxes III to cut the support of the Ionian towns for Cersebleptes, Philip finally felt confident enough to begin his most ambitious project so far: the conquest of inland Thrace in the form of a large campaign that would last from 342 to 340 BCE. Few details are known about this campaign. It seems to have started in May or June, when Philip's army penetrated the interior by marching upstream the Martisa river. The Odrysians resisted valiantly and confronted the Macedonians in many battles. Philip faced several setbacks and even seems to have lost at least one battle. By the spring of 341 BCE, fighting was still raging and Philip was forced to call in reinforcements. Although detailed evidence is lacking he finally managed to improve his situation and defeated Cersebleptes and Teres at some point between the second half of 341 BCE and the first half of 340 BCE.

Rise of the Getic kingdom
The Getae, a northern Thracian people located between the northeastern foothills of the Haemus range and the lower Danube and the Black Sea, had been part of the Odrysian realm since Teres I, even though it is not clear how tightly they were actually incorporated into the state. When and how the Getae became independent is not discussed in the available sources. Perhaps they became independent during the rule of Cotys I or after his death in 360 BCE. Rich funeral treasures from the second half of the 4th century, like those of Agighiol, Peretu or Borovo, attest to the increasing wealth of the Getic elite. Several artefacts seem to have originated in the Odrysian kingdom and may well have been prestige gifts.

By the middle of the 4th century BCE there existed a Getic kingdom that was to thrive for a century. The Getic capital was Helis, which has been identified with the archaeological site of Sboryanovo, which was founded in the 330s or early 320s BCE and housed around 10.000 inhabitants. It seems that the Getae also became active in Muntenia north of the Danube, a region that would come to constitute a part of the "Dacia" of imperial Pontic historiography. The first Getic king to appear in the sources was Cothelas, who married his daughter Meda to Philip II, thus concluding an alliance between the two states. This probably happened during or shortly after Philip's conquest of the Odrysians. The kingdom survived two wars with Lysimachus and the Celtic invasion in around 280 BCE, but eventually disintegrated a few decades later. Helis/Sboryanovo was completely destroyed by an earthquake in the middle of the 3rd century BCE.

Macedonian Thrace
The conquest of the Odrysian kingdoms doubled the size of the domains ruled by Philip II, even though inland Thrace was not transformed into a Macedonian province, but was put under the loose control of a Strategos. Local Thracian rulers who seemed trustworthy were allowed to rule on Macedonian behalf, granted that they would pay a tithe and provide troops. Such troops, generally called "Thracians" or "Odrysians", participated in the Macedonian conquest of Persia under Philip's successor Alexander the Great and were probably commanded by Odrysian noblemen. Philip founded several towns in Thrace to ease Macedonian rule, most prominently Cabyle and Philippopolis. The situation south of the Haemus remained largely stable for the next few years, albeit even here, Macedon never managed to impose its rule over all Thracian tribes. Macedon's rule was precarious and a potential Odrysian upstarter could count on the support of much of the disgruntled population.

Seuthes III and the Odrysian revival
With Alexander's absence in Asia, the Strategoi of Thrace engaged in rebellions and failed expeditions against the Getae, greatly unsettling the country in the process. At the end of the 330s or in the mid-320s BCE (the dating is not entirely clear), a certain Seuthes, later known as Seuthes III, instigated a Thracian rebellion. He seems to have been an Odrysian and may have been associated with the royal house of Cersebleptes, although his social background must remain speculation.

After Alexander's death in 323 BCE, one of his bodyguards named Lysimachus was appointed as the satrap of Thrace. Soon after his arrival he faced off with Seuthes, who had rallied much of Thrace around his banner. Seuthes' goal seems to have been the revival of an independent Odrysian state. A battle ensued between him and Lysimachus, which Lysimachus barely and by no means decisively won. Both sides prepared for a second conflict, but the primary source for this event, Diodorus Siculus, provides no details on its outcome.

In any case, both parties eventually reached a settlement, restricting Seuthes to the interior and Lysimachus to the coastal regions of the Aegean and Black Sea. There is no evidence for Lysimachus vassalizing Seuthes. Thrace north of the Rhodopes probably remained outside of Lysimachus' reach, as he may have regarded its pacification not worth the money and manpower. In 313 BCE Seuthes allied with revolting Greek towns on the western shore of the Black Sea, but Lysimachus defeated this alliance. It is possible that to guarantee the peace between the two opponents, Seuthes married a daughter of Lysimachus named Berenice. Afterwards, there is no evidence for another confrontation between the two.

Seuthes III, was keen to establish a Hellenistic kingdom, although he avoided to label himself as king on his coins. Probably after the death of Alexander in 323 BCE, Seuthes founded a town at the Tonzos river, near modern Kazanlak. He named it after himself: Seuthopolis. The town was primarily based on contemporary Macedonian foundations and showed heavy Greek influences. Seuthopolis probably acted as the capital of Seuthes' kingdom. The size and power of this kingdom should not be overestimated, as its influence was most likely limited to the hinterland of Seuthopolis, in particular the valley between the Rhodopes in the south to the Haemus in the north and the Syrmus in the west to the upper Tonzos in the east. Thus, his realm only covered the northwestern fringes of the former Odrysian empire. Seuthes also only issued bronze coins, which were insufficient to challenge the Macedonian economic hegemony and its royal mintings in more precious metals.

Fall of Seuthopolis
It is unknown when Seuthes III died, with estimations ranging from the end of the 4th century to the 280s BCE. Coins minted in his name include overstruck coins of Cassander (died 297 BCE) and Lysimachus (died 281 BCE), implying that his coins were produced until the early years of the 3rd century BC. Seuthes was symbolically buried in the tumulus of Golyama Kosmatka, without his actual corpse. It may well be that he had been killed in battle, perhaps fighting against Lysimachus or with him as an ally.

A long inscription from Seuthopolis attests to the decline of the fortunes of the town and the trouble in Seuthes' household. It mentions the wife of Seuthes, Berenice, and their four (probably underage) sons Hebryzelmis, Teres, Satocos and Satalas. The document was issued in the name of Berenice and includes the phrase "when Seuthes was in good health", which implies that by the time of writing, he was either dead or dying and that Berenice had taken the rule. The inscription describes negotiations between Berenice and Spartokos, the ruler of Cabyle, a town once founded by Philip II. Indeed, Cabyle had not remained a Macedonian fort for long, but began to mint coins and developed into a city-state with considerable influence. Spartokos is known from several coins minted after 281 BCE where he is addressed as king (basileus).

Although not mentioned in the Seuthopolis inscription and known only from a few coins and an inscription in a grave from Kazanlak, Seuthes seemed to have another son named Roigos, who eventually became king. The fate of Seuthes' dynasty remains enigmatic. Other Thracian monarchs recorded in sources from the 3rd century BCE, like Cotys or Scostocus, can not be proved to have been Odrysian, even if they are often labelled as such by modern authors.

The end of Seuthopolis is a matter of debatte, but it is clear that the town was destroyed still in the first half of the 3rd century. According to some scholars it was conquered by the Celts in the 270s BCE. The Celts were ravaging much of the Balkan Peninsula since the early 270s BCE and also led numerous incursions into Thrace. In c. 278 BCE and led by Comontorius, they eventually founded a kingdom in eastern Thrace centered around Tylis. A newer theory proposes the destruction of the town in the 250s BCE, based on a revamped dating of pottery, numismatic evidence and the presence of several Celtic artefacts. The archaeological evidence also shows the employment of siege artillery, which is unlikely to have been utilized by Celts. It may therefore be that Seuthopolis was not destroyed by the Celts, but by the Seleucid king Antiochus II, who campaigned in the Thracian interior in around 252 BCE.

Odrysians after 250 BCE and conquest by Macedon (250-189 BCE)
Most modern historians believe that the Odrysian kingdom continued to exist throughout the Hellenistic and the early Pontic period, when it became a Pontic vassal state. However, the evidence for this assumption is in fact very slim. Throughout the remainder of the 3rd century, Thrace remained fragmented into various political entities. In the interior ruled various badly known Thracian dynasts. In the east was the kingdom of Tylis, a Celtic-dominated predator state which existence was based on blackmailing tribute and that was eventually destroyed by a Thracian revolt or attack soon after 220 BCE. In the southeast and based at the town of Lysimachia, the Seleucids established themselves under Antiochus II (r. 261–246), who relied on allied Thracian dynasts to expand his influence deep into the interior. After his death in 246 BCE, the Seleucid presence was replaced by that of the Ptolemies, who established a satrapy in coastal Thrace. An Odrysian kingdom, however, is not described in the sources.

Almost nothing is known about Thrace in the years from 250 BCE to 213 BCE, however, we do know that the Odrysians still likely controlled parts of Thrace, however, though likely just referred to themselves as Thracians, rather than Odrysians.

Thracian League and conquest by Macedon
During the Second Social War (213–211 BCE), Philip V crushed the last opposition against Macedon in all of Greece. However, after defeating the Aetolian League, Philip V provoked Epirus into attacking the Achaean League, and shortly after attacked both nations and all other members of the Hellenic League, during the Third Social War (210-207 BCE). All of Greece was now under Macedonian control. Still, Thrace remained a rival and the Asian kingdoms were still opposing Macedonian hegemony, except Rhodes, which was allied to Macedon. These states were concerned about Philip V's alliance with Antiochus III the Great of the Seleucid Empire, which invaded the war-weary and financially exhausted Ptolemaic Empire in the Fifth Syrian War (202–195 BCE) as Philip V captured Ptolemaic settlements in the Aegean Sea. In result, the Kingdom of Thrace, Pergamon and Bithynia, formed the Thracian League.

In 192 BCE, Philip V and Antiochus III of the Seleucid Empire invaded the Kingdom of Thrace, Pergamon and Bithynia, in result of the Thracian League against Macedonia and his ally, the Seleucid Empire. This war is known as the Thracian War (192-189 BCE). The Seleucids and Macedonians had won this war, and the Seleucid Empire seized control over Pergamon and Bithynia, while Macedonia would occupy Thrace. This massive expansion of Macedonian territory, resulted in the proclamation of the Second Macedonian Empire by Philip V, in legacy of Alexander the Great.

After Pontos and short-lived Sassanid client state (235-238 CE)
After the collapse of the Pontic Empire in 235 CE, the Sasanians invaded Thrace, establishing a client state, eager to restore the boundaries of the Achaemenid Empire. However, in 238 CE, the Goths raided and invaded Thrace and established their own kingdom, waging wars with the Persians for decades to come.

After the Huns (458- CE)
After the retreat of the Huns, from Thrace, in 458, the Thracians managed to gain independence, establishing the Kingdom of Thrace. However, Thrace was in ruins; destroyed, plundered and devastated, like most of Eastern Europe. Even the Sassanids weren't eager to conquer Thrace, as there was almost nothing left anymore, and the Persians themselves had to recover from the Huns, and had to rebuild Mithripolis.

Odrysian Kingdom
The list below includes the known Odrysian kings of Thrace, but much of it is conjectural, based on incomplete sources, and the varying interpretation of ongoing numismatic and archaeological discoveries. Various other Thracian kings (some of them non-Odrysian) are included as well. Odrysian kings though called Kings of Thrace never exercised sovereignty over all of Thrace. Control varied according to tribal relationships. Odrysian kings:


 * Teres I, son of ? Odryses, (480/450/430 BC)
 * Sparatocus, son of Teres I (c. 465?-by 431 BC)
 * Sitalces, son of Teres I (by 431-424 BC)
 * Seuthes I, son of Sparatocus (424-396 BC)
 * Maesades, father of Seuthes II, local ruler in eastern Thrace?
 * Teres II, local ruler in eastern Thrace
 * Saratocus (= Sadocus, son of Sitalces?), local ruler in western Thrace?
 * Metocus (= Amadocus I?), son of ? Sitalces
 * Amadocus I, son of ? Metocus (unless identical to him) or of Sitalces (by 405-after 390 BC)
 * Seuthes II, son of Maesades, descendant of Teres I, local ruler in eastern Thrace (by 405?-after 387 BC)
 * Hebryzelmis, son or brother of ? Seuthes I (c. 386 BC)
 * Cotys I, son of ? Seuthes I or Seuthes II (by 384–360 or 359 BC)
 * Cersobleptes, son of Cotys I, king in eastern Thrace (360 or 359-341 BC)
 * Berisades, rival of Cersobleptes, king in western Thrace in Strimos (359-352 BC)
 * Amadocus II, son of Amadocus I and rival of Cersobleptes, king in central Thrace in Chersonese and Maroneia (359-351 BC)
 * Cetriporis, son of Berisades, king in western Thrace in Strimos (358-347 BC)
 * Teres III, son of ? Amadocus II, king in central Thrace in Chersonese and Maroneia (351-342 BC)
 * The kings of Thrace are forced to submit to Macedonian rule or overlordship by 341 BC
 * Seuthes III, son of ? Teres III or Cotys I, opposed Macedonian rule (by 324–after 312 BC)
 * The succession to Seuthes III is unclear; the area was partitioned among Thracian dynasts and Macedonian kings, after 277 also by the Celts of Tylis

Odrysian rulers in eastern Thrace (hypothetical reconstruction)

 * Cotys II, son of Seuthes (III?) (attested 330 BC, while still prince, if son of Seuthes III?)
 * Rhaezdus (Rhoegus?), son of ? Cotys II
 * Cotys III, son of Rhaezdus (c. 270 BC)
 * Rhescuporis I, son of Cotys III (?-by 212 BC?)

Odrysian rulers originally in inner Thrace (hypothetical reconstruction)

 * Teres IV, son of Seuthes (III?) (c. 295 BC?)
 * Seuthes IV, son of Teres (IV?)
 * Teres V, son of ? Seuthes IV (c. 255 BC)
 * Rhoegus, son of Seuthes (IV?) (mid-Third Century, buried in the Thracian Tomb of Kazanlak)


 * Seuthes V, son of ? Rhoegus

> Fall to Macedon in 189 BCE.

Source
https://en.wikipedia.org/wiki/Odrysian_kingdom

https://www.youtube.com/watch?v=qguBR8IWs90

https://en.wikipedia.org/wiki/List_of_rulers_of_Thrace_and_Dacia