In 1397, during the reign of Vasily I, Vologda was added to the Grand Duchy of Moscow. Subsequently, the city was several times attacked by Novgorod forces. During the Muscovite Civil War, Vologda played a key role. After Vasily II the Blind, the Grand Prince of Moscow, was defeated by Dmitry Shemyaka in 1447, he swore to never start a war against Shemyaka, was exiled to Vologda, and got the city as a personal possession. From there Vasily traveled to the Kirillo-Belozersky Monastery where the hegumen released him from the oath. The civil war continued, and in 1450, Vologda was besieged by the troops of Dmitry Shemyaka; however, they did not manage to occupy the town.