Pope Leo XI (; 2 June 153527 April 1605), born Alessandro Ottaviano de' Medici, was head of the Catholic Church and ruler of the Papal States from 1 April 1605 to his death in 27 April 1605. His pontificate is one of the briefest in history, having lasted under a month. He was from the prominent House of Medici originating from Florence. Medici's mother opposed his entering the priesthood and sought to prevent it by having him given secular honours, but after her death he eventually was ordained a priest in 1567. In his career he served as Florence's ambassador to the pope, Bishop of Pistoia, Archbishop of Florence, papal legate to France, and as the cardinal Prefect for the Congregation of the Bishops and Religious. He was elected to the papacy in the March 1605 papal conclave and served as pope for 27 days. Biography Early life Alessandro Ottaviano de' Medici was born in Florence as the son of Ottaviano de' Medici and Francesca Salviati. His family belonged to Medici di Ottajano, a cadet branch of the Medici family. He was also the great-nephew of Pope Leo X. Ottaviano died early in his son’s life, and thereafter Alessandro was home schooled by a Dominican priest, Vincenzo Ercolano. Alessandro felt the call to the priesthood, but his mother opposed this since he was the only male in the family. She sent him instead to the court of the Grand Duke of Tuscany, who appointed him a knight of San Stefano. In 1560 he travelled to Rome where he commenced a lifelong friendship and collaboration with Philip Neri, the future saint. It was Philip who predicted that Alessandro would ascend to the pontificate. His mother died in 1566, at which point he resumed his studies to become a priest. His ordination took place on 22 July 1567. Priesthood Alessandro served as the Florentine ambassador to Pope Pius V from 1569 to 1584 and in 1573 was appointed by Pope Gregory XIII Bishop of Pistoia. In March 1573 he received episcopal consecration in Rome. In 1574 he was made Archbishop of Florence. In 1583 he was made a cardinal by Pope Sixtus V and on 9 January 1584 received the title of Cardinal-Priest of Santi Quirico e Giulitta, after a titular church previously known as San Ciriaco alle Terme Diocleziane. In later years, , according to custom he would opt for other