Count François de Noailles was a pupil of Galileo's in Padua both at the university and privately. In 1603 this nobleman is mentioned in Galileo's account book for having paid him the due sum for lessons on the use of the geometric and military compass. Noailles recalled the instrument many years later when he asked his fellow disciple Benedetto Castelli (1577/8-1643) if it were possible to have a reproduction of it together with a copy of the book on its Operazioni, as he had lost both.
On his return to France Noailles served in the Royal Army and held many public offices. In 1632 he was appointed ambassador at Rome, but did not actually go there until 1634. Galileo, recalling that Noailles had been a pupil of his, sent his congratulations on the attainment of this appointment. As soon as Noailles was settled he contacted Castelli, and, along with him and with the Tuscan ambassador Francesco Niccolini (1584-1650), worked out a strategy for alleviating Galileo's detention at Arcetri. Despite Noailles' efforts, however, the stratagem failed and at the end of his mission all he could obtain was to meet Galileo on his way home to France. In the autumn of 1636, Noailles met Galileo in Poggibonsi. On this occasion Galileo gave a manuscript copy of his Discorsi e dimostrazioni sopra due nuove scienze [Discourses and Demonstrations concerning Two New Sciences] (Leiden, 1638) to Noailles, to whom the work would afterwards be dedicated.