The subject of an independent Finland was first mentioned in the 18th century, when present-day Finland was still ruled by Sweden. On 18 March 1742, during the Russian occupation in the Russo-Swedish War (1741–1743), Empress Elizabeth of Russia issued a proclamation in the Finnish language to the Finnish people asking them to create a Finland which would be independent from both Sweden and Russia. This led to preparations to create a Kingdom of Finland in 1742. The Finns elected Duke Peter of Holstein-Gottorp (who later became heir to the throne of Russia and Tsar as Peter III) to be the King of Finland. However, the political situation had outgrown the idea of Finnish independence and it quickly evaporated.