The third son of James C. Hozier of Newlands and Mauldslie Castle, Lanarkshire, Hozier was educated at Rugby School, Edinburgh Academy and the Royal Military Academy, Woolwich. He was successively lieutenant in the Royal Artillery, lieutenant in the 2nd Life Guards and captain in the 3rd Dragoon Guards, and passed first into and out of the Staff College, Camberley. He served with the Royal Artillery in the expedition to Peking, with the German Army in the War of 1866, as assistant military secretary to Sir Robert Napier in the Abyssinian expedition, and as assistant military attaché during the Franco-Prussian War. He was awarded the Iron Cross for his service in the latter conflict, made a Companion of the Bath in 1897, and a Knight Commander of the Bath in 1903.