Princess Augusta of Hesse-Kassel (German: Auguste Wilhelmine Luise von Hessen-Kassel; 25 July 1797 – 6 April 1889) was the wife of Prince Adolphus, Duke of Cambridge, the tenth-born child, and seventh son, of George III of the United Kingdom and Charlotte of Mecklenburg-Strelitz. The longest-lived daughter-in-law of George III, she was the maternal grandmother of Mary of Teck, wife of George V.

Princess and Landgravine Augusta of Hesse-Kassel, third daughter of Landgrave Frederick of Hesse-Kassel, and his wife, Princess Caroline of Nassau-Usingen, was born at Rumpenheim Castle (French: , German: ), Offenbach am Main, Hesse. Through her father, she was a great-granddaughter of George II of Great Britain, her grandfather having married George II's daughter Mary. Her father's older brother was the Landgrave of Hesse-Kassel. In 1803, her uncle's title was raised to Elector of Hesse — whereby the entire Kassel branch of the Hesse dynasty gained an upward notch in hierarchy.

On 7 May, in Kassel, and then, again, on 1 June 1818 at Buckingham Palace, Princess Augusta married her second cousin, the Duke of Cambridge, when she was 20 and he 44. Upon their marriage, Augusta gained the style HRH The Duchess of Cambridge. The Duke and Duchess of Cambridge had three children.

...
Wikipedia