 By the first half of the sixteenth century the Ottomans had begun their expansion into Iraq, waging wars against their arch rival, the Persian Safavids.In 1534, under the reign of Suleiman the Magnificent, Mosul was sufficiently secure within the Ottoman Empire and became the chief province (eyalet) responsible for all other administrative districts in the region.The Ottomans encouraged migration from Anatolia and the settlement of immigrant Turkmen along northern Iraq, religious scholars were also brought in to preach Hanafi (Sunni) Islam.