William I of Württemberg
On 24 January 1816, in Saint Petersburg, he married his first cousin, Grand Duchess Catherine Pavlovna of Russia (1788–1819), daughter of Emperor Paul I of Russia (1754–1801) and Princess Sophie Dorothea of Württemberg (1759–1828). The couple had two children:
Sophia Charlotte of Hanover
Sophia Charlotte of Hanover (30 October 1668 – 1 February 1705) was the first Queen consort in Prussia as wife of King Frederick I. She was the only daughter of Elector Ernest Augustus of Brunswick-Lüneburg and his wife Sophia of the Palatinate. Her eldest brother George Louis succeeded to the British throne in 1714 as King George I.