Advancing to relieve Kimberley at the beginning of the war, Methuen attempted a night attack at Belmont on 22/23 November 1899. He sent Colville off with his brigade to assault Gun Hill: although 'They were guided by my Brigade Major, Captain Ruggles-Brise, who led them to the exact spot', Colville admitted that he had miscalculated the distance, and that the commanding officer of 3rd Grenadier Guards attacked the wrong hill. Neither error was Ruggles-Brise's fault and he received his first Mention in Despatches for his work that night. He distinguished himself again at the Battle of Modder River and was present at the Battle of Magersfontein.