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:
Prince Paul of Württemberg
Paul and Friederike had a daughter named Adhelaide Paulina, alias Karoline, von Rothenburg (28 November 1805, Frankfurt am Main - 13 February 1872, Frankfurt am Main). On 16 February 1836, in Augsburg, Karoline married Karl, Baron von Pfeffel (22 November 1811, Dresden - 25 January 1890, Munich).