Leszek inherited the throne peacefully from Boleslaus the Bashful. Leszek, like other European kings attempted the risky policy of playing the nobility off against rising townsmen. Predictably this led to unrest and strenuous opposition from the nobility. Unable to mount a significant defense, Leszek fled Cracow and Poland to Hungary when the Mongols unsuccessfully attacked Cracow a year before his death. His death resulted in a protracted dynastic struggle.

Reigned 1279-1288