George disliked Robertson. Lloyd George suggested that Robertson be appointed Commander-in-Chief, India, but this job was already earmarked for Rawlinson. Lloyd George preferred Macready for the Irish job, as he had experience of peacekeeping duties in South Wales and Belfast as well as having served as Commissioner of the Metropolitan Police in London. Churchill again told the Prime Minister in February 1920 that he wanted Robertson, then protested that he had been overruled. He promoted Robertson to field marshal "as a consolation prize" on 29 March 1920, making him the only man ever to rise in the British army from private to field marshal. Wilson thought the promotion as "very disgusting". On returning to the UK, Robertson received no official welcome at Victoria Station and later recorded that "having secured a broken-down taxi I drove to my residence in Eccleston Square; and thereupon joined the long list of unemployed officers on half-pay". Later life Robertson was colonel of the 2nd Dragoons (Royal Scots Greys) from 9 March 1916 and colonel of the 3rd/6th Dragoon Guards from 31 December 1925. He became Colonel of the Royal Horse Guards in 1928; this made him Gold Stick and a member of the Royal Household. He was advanced to Knight Grand Cross of the Royal Victorian Order in 1931. On retirement Robertson's life savings had been a mere £600 (just over £20,000 at 2014 prices). He became chairman of the Brewers' Trustees and a director of British Dyestuffs Corporation as well as President of the British Legion. He became a director of the British Palestine Corporation and of the London General Omnibus Company – forty years later he was still remembered for his efforts on behalf of the men's welfare. Despite having made gifts to members of his family, on his death he left a modest fortune of £49,000 (almost £3,000,000 at 2014 prices). Although not a pacifist, in his later years Robertson often spoke out against the cost – both financial and human – of war. His interests were fishing, shooting and golf. Early in 1933 he told Edmonds that his chief regret was that he had never had a command in the field. He died from a thrombosis on 12 February 1933, aged 73. Mount Robertson in the Canadian Rockies and Sir William Robertson High School in his birth village, Welbourn, were named after him. His body was buried at Brookwood Cemetery.