She was George's first cousin - their father's were brothers. Her mother was a French noblewoman, Eleanor d'Olbreuse (1639-1723). Sophia Dorothea married George in 1682, when she was 16. They had two children - the future George II, and Sophia Dorothea (1687-1757), who became Queen of Prussia. Sophia Dorothea (the elder) had an affair with Count Philip von Koenigsmarck (sp?), a Swedish noble. A previous lover of the count discovered them and alerted George. He divorced Sophia Dorothea in 1694 and imprisoned her in the Castle of Ahlden, eventually making her Duchess of Ahlden, though she was never allowed see her children again. When her daughter became Queen of Prussia, she corresponded with her mother, and rumour says the future George II tried to swim the moat at Ahlden to see her but failed.