Pope Sixtus V, born Francesco Peretti in 1521, served as the head of the Roman Catholic Church from 1585 to 1590. He is known for his significant reforms in the Church and the administration of the Papal States. His papacy was marked by efforts to improve the efficiency of the Church and to combat corruption. One of his notable achievements was the completion of the Vatican and the establishment of a more organized system for the management of the Church's finances. Sixtus V also commissioned the construction of the Papal Basilica of St. Peter and the famous Sixtus V Obelisk in St. Peter's Square.