Gave papal approval to the Congregation of the Fathers of a Good Death (Clerici regulares ministrantes infirmis) founded by Saint Camillus de Lellis on 21 September1591.
Prohibited, on pain of excommunication, betting on the election of a pope, the length of his life or pontificate, or on the creation of cardinals, which were common practices in his day.
Ordered, on pain of excommunication, the freeing of all slaves in the Philippines.
Appointed a commission to revise the Sixtine Bible.
Appointed a commission to continue the revision of the Pian Breviary.
Gregory opposed Henry Navarre whom PopeSixtus V had declared a heretic.
Henry had ascended to the French throne in 1589 which caused civil disruption; the nobles swore to rise up against him if he remained a Protestant.
Henry promised to convert, but apparently had no intention to do so.
Gregory renewed the decree of excommunication and with the help of King Philip II of Spain he began to field an army to drive Henry from power.
However, before the matter was resolved, Gregory died, having reigned less than a year.