Roberto de' Nobili was born in Montepulciano on 17 September 1541, the son of Vincenzo de' Nobili, count of Civitella, and Maddalena Barbolani, the niece of Pope Julius III, from the family of the counts of Montauto. His paternal ancestry was that of the De Nobili family of Montepulciano.[1][2]
His family moved to Rome in 1550 when Pope Julius III was elected. As a boy he was tutored by Giulio Poggiano, Ottavio Pantagato, and Girolamo Ponzio, and by age ten was fluent in Latin and Ancient Greek. He also studied philosophy, literature, and the Scriptures.[1]