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:
Sophie of Pomerania, Duchess of Pomerania
As Eric refused to allow Sophia any of the political power over the territories he acquired through her, which she felt she was entitled to, the couple separated. Sophia moved to Rügenwalde Castle with her children and her lover, Hans of Maszerski. In 1470, she refused to finance her husband's war with Brandenburg. She was widowed in 1474.