Grand Duchess Maria Pavlovna of Russia
On 3 May 1908, in Tsarskoye Selo, Wilhelm married Grand Duchess Maria Pavlovna of Russia, a daughter of Grand Duke Paul Alexandrovich of Russia by his first wife Princess Alexandra of Greece and Denmark. The bride was a cousin of the reigning Russian tsar, Nicholas II. The couple had only one son: Prince Lennart, Duke of Småland and later Count of Wisborg (1909–2004).