Princess Mary Adelaide was born on 27 November 1833, in Hanover, Germany. She was the daughter of Princess Augusta of Hesse-Cassel (25 July 1797 - 6 April 1889) and Prince Adolphus, Duke of Cambridge (24 February 1774 - 8 July 1850). Her maternal grandparents were Princess Caroline Polyxene of Nassau-Usingen and Prince Frederick of Hesse. Her paternal grandparents were Charlotte of Mecklenburg-Strelitz, Queen Consort of the United Kingdom (19 May 1744 - 17 November 1818) and George III, King of the United Kingdom and Hanover (4 June 1738 - 29 January 1820). Mary Adelaide's parents were married on 7 May 1818, in Kassel, and then, on 1 June 1818, at Buckingham Palace, in London. Her siblings were: Prince George, Duke of Cambridge (26 March 1819 - 17 March 1904) and Princess Augusta of Cambridge (19 July 1822 - 4 December 1916). George IV died in 1830. He was succeeded by his brother, as William IV (- 20 June 1837). William IV died on 20 June 1837. He was succeeded by her cousin, Princess Victoria of Kent (1819-1901). As Salic law prevented Victoria from ascending the throne of Hanover, which instead passed to Prince Ernest Augustus, Duke of Cumberland, the Duke of Cambridge and his family returned to Great Britain, where they lived at Cambridge Cottage, Kew, and later at St. James's Palace. Mary Adelaide married Prince Francis of Teck on 12 June 1866, at Kew Church, in Surrey. They had four children.
The Children of Mary Adelaide, Duchess of Teck and Francis, Duke of Teck:
Princess Victoria Mary of Teck (26 May 1867 - 24 March 1953) Married Prince George, Duke of York in 1893.
Prince Adolphus of Teck (13 August 1868 - 23 October 1927) Married Lady Margaret Evelyn Grosvenor in 1894.
Prince Francis of Teck (9 January 1870 - 22 October 1910)
Prince Alexander of Teck (14 April 1874 - 16 January 1957) Married Princess Alice of Albany in 1904.
Mary Adelaide lived a life in luxury until 1883, when the Tecks were forced to flee the country to avoid their creditors. As the Count and Countess von Hohenstein, they travelled to Florence, Italy, Germany and Austria. In 1885, the family returned from exile and resided at White Lodge, in Richmond Park. Mary Adelaide began devoting her life to charity. In 1887, her husband was promoted to the rank of Highness to celebrate Queen Victoria's Golden Jubilee. Her mother, Augusta of Hesse-Cassel died on 6 April 1889. Her daughter, Mary married Prince George, Duke of York on 6 July 1893, at the Chapel Royal, in St. James's Palace, London. Mary and George's first child, a son, named Edward was born 23 June 1894. Mary Adelaide died aged 63, on 27 October 1897, at White Lodge, Richmond Park, Surrey. She was interred in the Royal vault, at St. George's Chapel, in Windsor.