The history of the Sudanese army: (Armies before 1900, Sudan Defence Force, Army of Independence, Egyptian Army, Militias)

Sudan has witnessed many armies throughout its long history, as each kingdom and state had some form of armed forces. However, the origin of the modern army dates back to the Sudanese soldiers recruited by the British during the re-occupation of Sudan in 1898. Sudan officially became the Anglo-Egyptian Sudan in 1899. The highest-ranking British officer in Egypt, known as the Sirdar, also held the position of Governor-General of Sudan. In 1922, after the nationalist riots caused by the Egyptian leader Saad Zaghloul, the United Kingdom granted independence to Egypt. The Egyptians wanted more influence in Sudan and established specialized units of Sudanese auxiliaries within the Egyptian army called the "Otraya". These became the nucleus of the modern Sudanese army.

The British army formed the Sudan Defence Force (SDF) as a local auxiliary force in 1925. The SDF consisted of a number of separate regiments. Most of them were Muslim soldiers concentrated in the North, but the Otraya Corps in the South consisted of Christians. During the Second World War, the SDF participated in the war alongside the Allied forces that engaged the Italians in Ethiopia. They also served during the Western Desert campaign and supported the operations of the Free French forces in the desert and in the oases of Kufra and Jalo in the Libyan Desert. The SDF operated side-by-side with units of the British army, but all British forces had disappeared from Sudan by 1955. The Otraya Corps in Torit mutinied on August 18, 1955, shortly before independence, leading to the formation of the Anyanya movement and the First Sudanese Civil War. Orders were issued for a division of the Otraya Corps to move to the North, but instead of obeying, the forces mutinied with other Southern soldiers in Juba, Wau, Yambio, and Maridi. This mutiny was the nucleus of a long civil war that ended with the secession of the South.