The IX Corps of the Ottoman Empire (Turkish: 9 ncu Kolordu or Dokuzuncu Kolordu) was one of the corps of the Ottoman Army. It was formed in the early 20th century during Ottoman military reforms. Formation Order of Battle, 1911 With further reorganizations of the Ottoman Army, to include the creation of corps level headquarters, by 1911 the IX Corps was headquartered in Erzurum. The Corps before the First Balkan War in 1911 was structured as such: IX Corps, Erzurum 28th Infantry Division, Erzurum 82nd Infantry Regiment, Erzurum 83rd Infantry Regiment, Erzurum 84th Infantry Regiment, Hasankale 28th Rifle Battalion, Yemen 28th Field Artillery Regiment, Erzurum 28th Division Band, Erzurum 29th Infantry Division, Bayburt 85th Infantry Regiment, Bayburt 86th Infantry Regiment, İşhan 87th Infantry Regiment, Trabzon 29th Rifle Battalion, Erzurum 29th Field Artillery Regiment, Bayburt 29th Division Band, Trabzon Units of IX Corps 9th Rifle Regiment, Erzurum 21st Cavalry Regiment, Erzurum 2nd Horse Artillery Battalion, Erzurum 9th Engineer Battalion, Erzurum 9th Transport Battalion, Erzurum Erzurum Fortified Area Command, Erzurum 12th Heavy Artillery Regiment, Erzurum Engineer Platoon, Erzurum Border companies x 12 Balkan Wars Order of Battle, July 1913 IX Corps (Caucasus) 33rd Division World War I Order of Battle, August 1914 In August 1914, the corps was structured as follows: IX Corps (Caucasus) 17th Division, 28th Division, 29th Division, 9th Cavalry Brigade Order of Battle, November 1914, Late April 1915, Late Summer 1915, January 1916, August 1916 In November 1914, Late April 1915, Summer 1915, January 1916, August 1916, the corps was structured as follows: IX Corps (Caucasus) 17th Division, 28th Division, 29th Division Sources Corps of the Ottoman Empire Military units and formations of the Ottoman Empire in World War I History of Erzurum 1911 establishments in the Ottoman Empire