[2] 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.

Ottaviano died early in his son's life, and thereafter Alessandro was home schooled by a Dominican priest, Vincenzo Ercolano.

[4] 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.

[3][6] In 1596 Pope Clement VIII sent Alessandro as a papal legate to France, where he remained until 1598, when he received word of his appointment as Prefect of the Congregation of Bishops and Regulars.

Prominent among the candidates for the papacy were the great historian Caesar Baronius and the famous Jesuit controversialist Robert Bellarmine, future saint.

[9] His death came as a result of fatigue and cold in the ceremony of taking possession of the Basilica of St John Lateran on 17 April; he started suffering from a fever the following day.