[3] After promotion to colonel on 27 August 1898, he then took part in the Second Boer War (1899–1902), being present at the defence of Ladysmith in 1900.

[2] Knox stayed in South Africa until after the war ended in May 1902, and two months later left by the SS Briton for Southampton.

[4] For his service in the war, he was mentioned in despatches (including by Lord Kitchener dated 23 June 1902),[5] received the Queen's South Africa Medal,[3] and was appointed a Knight Commander of the Order of the Bath (KCB) in the April 1901 South Arica Honours list (the order was dated to 29 November 1900,[6] and he was only invested as such after his return home, by King Edward VII at Buckingham Palace on 24 October 1902).

[7] Following his return to the United Kingdom, Knox was on 9 September 1902 appointed a Major-General on the Staff Commanding Royal Artillery of the 3rd Army Corps, stationed in Ireland.

[8][9] He was appointed General Officer Commanding 8th Division in Southern Ireland in 1905 before retiring in 1910.