 He later took his degree in 1906, gaining a third.Maitland was commissioned a second-lieutenant in the Essex Regiment on 23 May 1900, and served with the 2nd battalion of his regiment in the Orange River Colony during the Second Boer War in South Africa.He was promoted to lieutenant on 26 January 1902, and returned home with his battalion in October that year, after the end of the war three months earlier.