Grand Prince Ivan III of Russia pursued expansionist policies, which strained Moscow's relations with Livonia. In 1492, Moscow built Ivangorod Fortress opposite of Narva and two years later closed down the Hanseatic office in Novgorod. Hanseatic merchants, most of them Livonians, were imprisoned. The trade through Tallinn and Tartu diminished significantly. During the Russo-Swedish War (1495–1497), Sweden captured Ivangorod and offered it to Livonia, an offer which was refused. Moscow perceived that as a Swedish–Livonian alliance. As negotiations failed, Livonia began preparing for war. In May 1500, a war broke out between Moscow and the Grand Duchy of Lithuania. On 17 May 1501, Livonia and Lithuania concluded a ten-year alliance in Vilnius. In August 1501, von Plettenberg led a Livonian a