Hertling assumed responsibility for all Coalition forces in Northern Iraq. Multi-National Division North was composed of five maneuver brigade combat teams, a combat aviation brigade, a fires brigade, and an engineer brigade. The division had responsibility includes the Iraqi provinces of Ninawa, Kirkuk (formerly at Tamin), Salah ad Din, and Diyala along with Dahuk, and As Sulaymaniyah. The area included the critical cities of Tal Afar, Mosul, Bayji, Tikrit, Kirkuk, Samarra, Balad, Baqubah, Dahuk, and Sulaymaniah. Arbil province remained aligned as a separate Multi-National Division, North-East. The division area of operations included ethnic fault lines between Arabs and Kurds, religious fault lines between Sunni and Shia Muslims, numerous tribal regions, and the complexities involving significant former regime elements.