Pope Adrian V, born Ottobuono de' Fieschi, was the head of the Catholic Church and ruler of the Papal States from 11 July 1276 to his death on 18 August 1276. He was an envoy of Pope Clement IV sent to England in May 1265 who successfully completed his task of resolving disputes between King Henry III of England and his barons. Adrian V was elected pope following the death of Innocent V, but died of natural illness before being ordained to the priesthood.

Pope Innocent V, born Pierre de Tarentaise, was head of the Catholic Church and ruler of the Papal States from 21 January to 22 June 1276. A member of the Order of Preachers, he acquired a reputation as an effective preacher. He held one of the two "Dominican Chairs" at the University of Paris, and was instrumental in helping with drawing up the "program of studies" for the Order. In 1269, Peter of Tarentaise was Provincial of the French Province of Dominicans. He was a close collaborator of Pope Gregory X, who named him Bishop of Ostia and raised him to cardinal in 1273.