Odrysian kingdom

The Odrysian kingdom was an ancient Thracian state that thrived between the early fifth century BC and the early third — or late first — century BC, located in present-day Bulgaria, southeastern Romania (Northern Dobruja), northern Greece and European Turkey. It was a tribal amalgam dominated by the Odrysians and the first large political entity to develop in the eastern Balkans; before the foundation of Seuthopolis in the late fourth century BC it had no fixed capital, the king's authority moving with the royal household among the tribes. The kingdom was founded by king Teres I, exploiting the collapse of the Persian presence in Europe after the failed invasion of Greece in 480–79 BC — the dawn of the period the map records. Teres and his son Sitalces pursued a policy of expansion that made 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 the Athenian side. By 400 BC the state showed the first signs of fatigue, although the skilled Cotys I initiated a brief renaissance that lasted until his murder in 360 BC. Afterwards the kingdom disintegrated into weaker successor realms, surviving under shifting dominance until the Romans organized the province of Thrace, the end date of the record.