Pope Gregory XIII

Pope Gregory XIII (1502-1585) was the Supreme Pontiff of the Catholic Church from 1572 to 1585. As Pope, he decreed that the Julian Calendar be abandoned in favor of the more accurate Gregorian Calendar in all Catholic countries.

He was very concerned about the growing strength of England under the Protestant Queen Elizabeth and encouraged the King of Spain, Philip II, whom he had served as a legate prior to his election to the papacy, to overthrow Elizabeth. He promised to pay Philip one million gold ducats from the Vatican treasury when the first Spanish soldier landed on England, a promise which was kept by his successor, Pope Sixtus V.

Lope de Vega encouraged William Shakespeare to depict this episode in his play King Philip. As the promise had been made through agents rather than in a direct meeting between the Pope and the King, Shakespeare complained that the action would be very difficult to portray in an interesting fashion.