John H Casimir Vasa

After

An unhappy kingship, he abdicated and retreated into the church once more, becoming a Jesuit abbot

Constant war, and he would be the last of the Vasas in the Polish-Lithuanian Commonwealth.

John Casimir soon even married his brother's widow queen Marie Louise Gonzaga, a woman he had met years before when he acted as a proxy in the place of Wladyslaw during their wedding itself, for his brother could not be present. Casimir's reign was one filled with war, from the Russo-Polish War between 1654 and 1667 to The Swedish Deluge from 1655 to 1660, representing the climax of a series of wars that had taken place in Poland-Lithuania in the mid-17th Century, which ultimately resulted in the Commonwealth losing an estimated 40 per cent of its population and arguably its status as a great power within Europe. Perhaps unsurprisingly, it was also because of the once-lost Swedish throne so desperately desired by Casimir's father that the foundations of such a devastating war were ever even built. The Swedish Empire had become one of the strongest nations in the world and boasted a huge army. King John Casimir continued to be regarded as a weak, 'Jesuit' king, lacking support from the Commonwealth nobility because of his disdain for their culture; The Polish-Lituanian Commonwealth was already weakened, preoccupied with sustaining its other wars such as the Russo-Polish War to the east. The time was ripe to invade from the west.

Most of Poland was overrun by the Swedish army without much resistance, and the damages to Casimir's homeland were more extensive than even the destruction it later sustained during

Defining moment