Thracian warriors in Alexander the Great's army
The Thracians were a Balkan tribe who inhabited large parts of Eastern Europe and the Balkans in ancient history. The ancestors of the Thracians were pushed out of Ukraine and into the Balkans by the tribes of the Srubnaya culture, and these ancestors intermarried with the Indo-Europeans on their arrival in the region in 1500 BC. During the Iron Age, this people split into the Thracians and the Dacians, and the Thracians came to be known as fierce warriors and sought-after mercenaries who lived in simple, open villages, developed their own poetry and music, and were prevented from conquering the Balkans only because of thier political fragmentation. In the early 6th century BC, the Achaemenid Empire of Persia conquered Thrace, forcing the Thracians to join their multinational army amid the Greco-Persian Wars. By the 5th century BC, Herodotus recorded that the Thracians were the second-most populous people in the known world after the Indians. From the 5th century BC to 1st century AD, the Thracians formed the Odrysian Kingdom, which ruled over 40 tribes and 22 kingdoms in Bulgaria, southeastern Romania, and parts of northern Greece and Rumelia. In 279 BC, the Celts invaded the Balkans, and the Scordisci tribe became neighbors with the Thracians. During the Macedonian Wars, the Thracians gained regional power as the might of Macedon declined, and the Thracians joined the Macedonians in several revolts against the Roman Republic. After the Third Macedonian War, Thrace became a Roman client state, and it was incorporated into the Roman Empire in 46 AD after the murder of King Rhoemetalces III. The Empire never attempted Romanization of the Thracians due to a lack of urban centers, but Thracians in Moesia were Romanized. The later invasions of Huns, Goths, Scythians, Sarmatians, and Slavs led to the reduction of Thracian cultural influence in Thrace, and, during the late 4th century AD, the Thracians were introduced to Christianity. The remnants of the Thracians were gradually assimilated into Roman and Byzantine society and ultimately underwent Slavicization, becoming the ancestors of the Bulgarians and other peoples of the Balkans.