a German prince and a younger son of Frederick III, Elector Palatine. A firm Calvinist, he was a leader of mercenary troops in the religious wars of the time, including the Dutch Revolt. From 1583–1592 he acted as regent for his nephew, Elector Palatine Frederick IV. ohn Casimir was in regular contact with Robert Dudley, 1st Earl of Leicester and his nephew Sir Philip Sidney who, as agent for Elizabeth I, was sent to the continent to assist in the formation of a Protestant league. In 1576, John Casimir entered France leading four thousand troops.
