The Parthians (247 BC – 224 AD) from Persia conquered the region during the reign of Mithridates I of Parthia (r. 171–138 BC). From Syria, the Romans invaded western parts of the region several times, briefly founding "Assyria Provincia" in Assyria. Christianity began to take hold in Iraq (particularly in Assyria) between the 1st and 3rd centuries, and Assyria became a centre of Syriac Christianity, the Church of the East and Syriac literature. A number of independent states evolved in the north during the Parthian era, such as Adiabene, Assur, Osroene and Hatra.