Together with the Diet of Porvoo (1809), and the Oath of the Sovereign,[3] the Treaty of Fredrikshamn constitutes the cornerstone for the autonomous Grand Duchy, its own administration and institutions, and thereby a start of the development which would lead to the revival of Finnish culture, to equal position of the Finnish language, and ultimately in 1917 to Finland's independence.

At the period of Russification of Finland, 90 years later, the Russian government argued that the treaty was not violated and hence no outside party had any right to intervene, the question being solely a matter of the Emperor who had granted the original promise.

During the negotiations, Swedish representatives had namely endeavoured to escape the loss of the Åland islands, "the fore-posts of Stockholm," as Napoleon rightly described them.

The Åland islands were culturally, ethnically and linguistically purely Swedish, but such facts were of no significance at that time.

During the War of the Sixth Coalition, Russia and Sweden concluded an alliance directed against France (5 April 1812).