The Siege of Smolensk of 1514 took place during the fourth Muscovite–Lithuanian War (1512–1520). The growing and strengthening Grand Duchy of Moscow clashed with the Grand Duchy of Lithuania over the territories of the former Kievan Rus'. The tension resulted in a series of wars from 1492. In November 1512, the war resumed again. The main objective of Moscow was to capture Smolensk, an important fortress and trade center, that was part of Lithuania since 1404. The Russians, commanded personally by Tsar Vasili III of Russia, laid a six-week siege in January–February 1513, but Grand Hetman Konstanty Ostrogski repelled the attack. Another four-week siege followed in August–September 1513.