At the Hanoverian court she formed a close attachment to Count Philip Christoph von Königsmarck, a Swedish soldier, and they planned to flee together. Her marriage was dissolved later that year, and she was forbidden to remarry or to see her children. She was confined at Ahlden House in the duchy of Celle, where she was known as the Princess of Ahlden. Sophia Dorothea spent more than thirty years at Ahlden. The death of her mother in 1722 left Sophia Dorothea alone. When Sophia Dorothea's daughter, the Queen in Prussia, travelled to Hanover in 1725 to see her father, by then King George I of Great Britain, Sophia Dorothea, dressed even more carefully than usual, and waited every day at the window of her residence, hoping in vain to see her daughter. Sophia Dorothea grew overweight, and was frequently plagued by febrile colds and indigestion. In early 1726, she suffered a stroke; in August of that year she went to bed with a severe colic, and refused all food and treatment. She died shortly before midnight on 13 November 1726, aged 60. An autopsy revealed liver failure and gall bladder occlusion due to 60 gallstones. Her former husband placed an announcement in The London Gazette to the effect that the Duchess of Ahlden had died, but he forbade mourning in either London or Hanover. He was furious when he heard that the members of his daughter's court in Berlin were wearing black.