On 29 March 1809, having been taken over by the armies of Alexander I of Russia in the Finnish War, Finland became an autonomous Grand Duchy in the Russian Empire with the recognition given at the Diet held in Porvoo. This situation lasted until the end of 1917. In 1811, Alexander I incorporated the Russian Vyborg province into the Grand Duchy of Finland. In 1854, Finland became involved in Russia's involvement in the Crimean War, when the British and French navies bombed the Finnish coast and Åland during the so-called Åland War. During the Russian era, the Finnish language began to gain recognition. From the 1860s onwards, a strong Finnish nationalist movement known as the Fennoman movement grew, and one of its most prominent leading figures of the movement was the philosopher J. V. Snellman, who was strictly inclined to Hegel's idealism, and who pushed for the stabilization of the status of the Finnish language and its own currency, the Finnish markka, in the Grand Duchy of Finland. Milestones included the publication of what would become Finland's national epic – the ''Kalevala'' – in 1835, and the Finnish language's achieving equal legal status with Swedish in 1892.