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:
Princess Sophie of Hohenberg
Princess Sophie was born on 24 July 1901 at Konopiště chateau, in Austria-Hungary, (now the Czech Republic), fifty kilometres south-east of Prague. This chateau, situated in Bohemia, was the favourite home of the Archduke and his wife. On 29 September 1902, the couple's first son, Maximilian, was born. A second son, Ernst, followed on 17 May 1904. In 1908, the Archduke's wife became pregnant again, but the fourth child, a boy, was stillborn on 7 November 1908.