Anna of Russia
Meanwhile, Friedrich Wilhelm Kettler had married Anna of Russia. When Friedrich Wilhelm died, he left Ferdinand as the last heir to the throne of Courland from the House of Kettler. However, Ferdinand was reluctant to return, and the duchy was instead ruled by Anna of Russia, who acted as regent. In 1725, the Council of the Duchy elected Maurice de Saxe as the new duke. However, he soon left Courland because of friction with the Russian imperial administration.