Ugo Boncompagni, born in 1502, was an influential Italian cardinal and the Pope known as Pope Gregory XIII. He is best remembered for his role in the reform of the calendar, leading to the creation of the Gregorian calendar in 1582. This calendar corrected inaccuracies in the previous Julian calendar and is the system most widely used today. Boncompagni was also a patron of the arts and education, supporting various cultural and scholarly endeavors during his papacy. His contributions to the Catholic Church and European society had a lasting impact, shaping both religious practices and the way time is measured.