During the Time of Troubles, the monastery not only became a center for the consolidation of Russian society, but also contributed its own page in military history. For sixteen months—from October 1608 to January 1610—it withstood the siege of the Polish forces. In the side door of Trinity Church, close to the reliquary of St. Sergius, is a large hole, made by a cannonball that hit the church. It has been specially retained in the memory of those events.