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:
Countess Palatine Dorothea Sophie of Neuburg
Born at the , Countess Palatine Dorothea was the fourteenth of seventeen children and her parents' sixth daughter. Her older sisters included: Eleonor Magdalene, consort of Holy Roman Emperor Leopold I; Maria Sofia, consort of Peter II of Portugal; Maria Anna, consort of Charles II of Spain; and Elisabeth, daughter-in-law of John III Sobieski, King of Poland.