 Educated at Clifton College, he was commissioned into the Scots Guards as a second lieutenant on 29 December 1888, promoted to lieutenant on 13 April 1892, and to captain on 24 June 1899.When the Second Boer War broke out in October 1899, the 1st battalion of the Scots Guards departed Ireland for South Africa to join up with the 1st Guards Brigade, with Lowther appointed adjutant.They reached that country in November, and immediately saw action in the battles of Belmont and Modder River, both British victories, though at a heavy cost in British life.