Armenia is one of the cradles of human civilization with a recorded history of about 3,500 years. Located in the south Caucasus area of Eurasia, Armenia was settled in the Neolithic era but its first recorded state proper was the kingdom of Urartu from the 9th century BC. Incorporated into the Persian Empire of Cyrus the Great in the 6th century BC, the Orontid dynasty ruled as Persian satraps, a function they performed for their next overlords the Macedonians and Seleucid Empire into the 3rd century BC. Under the Artaxiad and Arsacid dynasties the country flourished but was often caught between the ambitions of Parthia and Rome, and then the Sasanian and Byzantine Empires. The boundaries of the state varied considerably over the centuries but such common factors as religion and language were united by long-lasting dynastic clans, which gave Armenia its own unique identity throughout antiquity.