Kalec's origins begin in the 13th century, it was a modest establishment with a bunker, inhabited by families of the low nobility formed during the middle age. Kalecs steps to be a part of the Monastery of Plasy caused disputes between several feudal entities until 1346. In the 14th century the monastery began to acquire properties in this establishment. During the period of the Battle of White Mountain in the 30 Years War against Sweden, Kalec was occupied several times, including by Emperor Frediand II.