Assyria, a major Mesopotamian East Semitic kingdom and empire of the Ancient Near East, existed as an independent state for from perhaps as early as the 25th century BC, until its collapse between 612 BC and 599 BC, spanning the mid to Early Bronze Age through to the late Iron Age. From the end of the 7th century BC to the mid-7th century AD, it survived as a geo-political entity, for the most part ruled by foreign powers, although a number of small Neo-Assyrian states such as Assur, Adiabene, Osroene, Beth Garmai and Hatra arose at different times during the Parthian and early Sassanid eras, between the mid 2nd century BC and late 3rd century AD, a period which also saw Assyria become a major centre of Syriac Christianity and the birthplace of the Church of the East.