When did Pope Gregory XIII hold the papacy?
Pope Gregory XIII
Pope Gregory XIII (Latin: Gregorius XIII; 7 January 1502 – 10 April 1585), born Ugo Boncompagni, was Pope of the Catholic Church from 13 May 1572 to his death in 1585. He is best known for commissioning and being the namesake for the Gregorian calendar, which remains the internationally accepted civil calendar to this day.
1903 papal conclave
The pontificate of Leo XIII came to an end on 20 July 1903 after 25 years, longer than any previous elected Pope, except his predecessor Pius IX; together, they had reigned 57 years. While Pius had been a conservative reactionary, Leo had been seen as a liberal, certainly in comparison with his predecessor. As cardinals gathered, the key question was whether a pope would be chosen who would continue Leo's policies or return to the style of papacy of Pius IX.