When did Pope Gregory XIII hold the papacy?
Pope Gregory VIII
Gregory died in Pisa on 17 December 1187 of a fever after holding the papacy for only 57 days. He was buried in the Duomo in Pisa. He was succeeded by Pope Clement III. According to Joseph S. Brusher, "His pontificate though brief was glorious."
Teodolfo Mertel
Mertel participated in the conclave of 1878, which elected Pope Leo XIII. During the coronation ceremonies, Mertel served as protodeacon and crowned the new pope, since the Cardinal Protodeacon, Prospero Caterini, was unable to do so due to illness. In 1881 he became the Cardinal Protodeacon upon the death of Cardinal Caterini and he also chose to have his title changed to that of the Church of Santa Maria in Via Lata formerly held by the late cardinal.