By 1925, the grand duke had become so troublesome that his son-in-law, Harold, regarded him as "perfectly crazy". On 4 September 1927, his wife died, aged fifty-nine. King George V wrote a letter of condolence and the Prince of Wales attended her funeral. By November, according to Harold, the grand duke was again behaving well, as he no longer had his wife to argue with. He survived her for less than two years. Grand Duke Michael contracted influenza and died in London on 26 April 1929, aged sixty-seven. He was buried with his wife in Hampstead Cemetery.