As the frontiers of the Russian Empire gradually pushed further west, Kuressaare lost its strategic value. Especially after the Finnish War and the Third Partition of Poland, military focus shifted away from Estonia. In 1836, following the construction of the fortress of Bomarsund on Åland, the Russian garrison at Kuressaare withdrew. The fact that Kuressaare castle was not employed by the armies who fought in the Crimean War is also indicative of its lost strategic importance. In the 19th century, the castle was used as a poorhouse.