Later life and death
With an Order in Council on 1 July 1887, Queen Victoria granted Francis the style of Highness, as a gift to celebrate her Golden Jubilee. Despite this, the Tecks were still seen as minor relatives, with little status or wealth. Their fortunes improved when their only daughter, Princess Victoria Mary of Teck (known as "May" to her family) became engaged to the second-in-line to the British throne, Prince Albert Victor, Duke of Clarence and Avondale. There was initial opposition to the match from the Duke of Clarence's parents, the Prince and Princess of Wales. Arthur Balfour wrote to Lord Salisbury in 1890 that "(t)he Teck girl they won't have because they hate Teck and because the vision of Princess Mary haunting Marlborough House makes the Prince of Wales ill." Nevertheless, the Queen gave her official consent to the engagement on 12 December 1891. The death of the Duke of Clarence only six weeks later was a cruel blow. However, Princess May consented when the Duke of Clarence's brother (and next in the line of succession), Prince George, Duke of York, proposed to her instead.
In Who's Who, the Duke of Teck listed his recreations as "a little of all". He was President of the Royal Botanic Society and a member of numerous club, including White's, the Marlborough Club, the Bachelors' Club, the Army and Navy Club, the United Service Club, the Cavalry Club, the Naval and Military Club, the Travellers Club, The Hurlingham Club, the Ranelagh Club, and the Jockey Club, as well as the Adels-Casino in Vienna and the Herren-Casino in Stuttgart.
By 1897 the Duke, who had always been irascible, was experiencing memory problems and had difficulty remembering words. After the death of his wife that year Teck became mentally unhinged. The Duchess left no will, causing further financial problems. He was sent to Stuttgart to stay with his cousin the Duke of Wurtemberg, where his deranged rantings brought on another stroke and he had to return to England; he stayed at White Lodge under the care of a doctor and four medical attendants. He was last visited by his daughter May (the future Queen Mary) in October 1898, by which time he had a white beard and was barefoot in a nightgown; he recognised his daughter but she was asked not to visit him again as her visit had agitated him. For the last year of his life he was, in the medical language of the time, “an imbecile”.
Teck died of another stroke on 21 January 1900 at White Lodge. He was buried next to his wife in the Royal Vault at St George's Chapel, Windsor Castle.
There is a pub in Earls Court, London, called the Prince of Teck.