William Doran was recorded as being at the Royal Military Academy Sandhurst on 3 April 1881. He was commissioned as a subaltern in Her Majesty's Royal Irish Rifles on 10 May 1882. He deployed with his regiment to Egypt and took part in the Anglo-Egyptian War of 1882 and later the Sudan Expedition of 1884-85. In late November 1899 he took part in the operations leading to the defeat of the Khalifa, and for his services in the Sudan he received the brevet rank of lieutenant-colonel on 14 March 1900.