He was chief archivist of the Vatican Secret Archives (which now holds over 85 linear kilometres of shelving),[1] from 17 February 1618 until his death on 29 June 1626.

He became domestic secretary to Pope Paul V, who appointed him in 1611 to a position in the Papal Curia and in 1615, custodian of the Archive of Castel Sant'Angelo.

He was a member of the Inquisition and one of the cardinals who questioned Galileo after he came to Rome, and also of the Congregation for the Propagation of the Faith, created on 6 January 1622, to which he gave 100 scudi a year for ransoming prisoners of the Turks.

He was considered to belong to the French faction and with a reputation as a "spiritual" man, was one of the major candidates to succeed him, Pope Urban VIII was elected.

Deeply revered for his writings and promoting religious order, he was buried in a tomb with a plaque extolling his virtues and contributions and depicting his heraldic arms.