Pope Sixtus IV (or Xystus IV, ; born Francesco della Rovere; (21 July 1414 – 12 August 1484) was head of the Catholic Church and ruler of the Papal States from 9 August 1471 until his death in 1484. His accomplishments as pope included the construction of the Sistine Chapel and the creation of the Vatican Library. A patron of the arts, he brought together the group of artists who ushered the early Renaissance into Rome with the first masterpieces of the city's new artistic age. Wikipedia