Jan Kazimierz Waza
Jan Kazimierz Waza (1609-1672) - Polish elected king and Lithuanian Grand Duke of the Vasa dynasty, son of Zygmunt III. In his youth, he was a prisoner of Cardinal Richelieu and spent two years in a French fortress, on suspicion of espionage. He briefly entered the Jesuit order, and in 1646 he even became a cardinal, which, however, did not prevent him from returning to the secular state.
He was elected monarch in the fall of 1648 and ascended to the throne in January 1649, after the death of his older brother, Władysław. Four months after the coronation, he married his brother's widow, Ludwika Maria Gonzaga.
He reigned during the Cossack uprisings led by Bohdan Chmielnicki (1648-1657), the devastating Swedish Deluge (1655), which briefly forced him to flee the country, and the Polish-Russian war (1654-1667), which ended with the loss of a huge part of the Grand Duchy of Lithuania .
After the death of his wife, he was the only king in the history of Poland who voluntarily relinquished power. Abdicated in 1668, then he went to France, where he became abbot of the monastery in Saint-Germain-des-Prés. Historians consider him one of the worst rulers.