Answer
The abdication of John II Casimir Vasa, King of Poland and Grand Duke of Lithuania, was precipitated by a series of revolts, most notably the Lubomirski Rebellion led by Jerzy Sebastian Lubomirski. These uprisings, fueled by internal political dissent and conflicts, as well as external factors like the Swedish invasion, created an untenable situation for John Casimir, leading to his ultimate decision to relinquish the throne in 1668.