[3] Maxwell was 28 years old, and a lieutenant attached to Roberts's Light Horse during the Second Boer War when the following deed took place for which he was awarded the VC: On 31 March 1900 at Sanna's Post (aka Korn Spruit), South Africa, Lieutenant Maxwell was one of three Officers not belonging to "Q" Battery, Royal Horse Artillery, specially mentioned by Lord Roberts as having shown the greatest gallantry, and disregard of danger, in carrying out the self-imposed duty of saving the guns of that Battery during the affair at Korn Spruit on 31st March, 1900.

During a previous Campaign (the Chitral Expedition of 1895) Lieutenant Maxwell displayed gallantry in the removal of the body of Lieutenant-Colonel F. D. Battye, Corps of Guides, under fire, for which, though recommended, he received no reward.

[4]Major Edmund Phipps-Hornby, Sergeant Charles Parker, Gunner Isaac Lodge and Driver Horace Glasock also earned the Victoria Cross in this action.

Following the end of hostilities in early June 1902, he left Cape Town on board the SS Orotava together with Lord Kitchener,[5] and arrived at Southampton the next month.

[8][9] He was promoted to the temporary rank of lieutenant colonel in November 1910, while serving as military secretary to the viceroy and governor general of India.

His brother, Lieutenant Colonel Eustace Lockhart Maxwell of the 11th King Edward's Own Lancers (Probyn's Horse), was killed on 20 July 1916 during the Battle of the Somme, whilst commanding the 'bantams' of 23rd Manchester Regiment.

[20] Maxwell's medals are now held in the Imperial War Museum as part of the "Lord Ashcroft collection" having been bought at auction for £78,000.