Gregory X (1210-1276) was elected pope in 1271, after the office had been vacant for almost three years. He issued an important reform decree that regulated papal elections to avoid long vacancies in the future. See Pope (The election of a pope [Early days]) .
Gregory was born in Piacenza, Italy. His given and family name was Tedaldo Visconti. A deeply religious man of great intellect, he studied theology in Paris. Gregory was in the Holy Land when he learned of his election as pope. He soon called for a general council at Lyons. He hoped that the council would revive the crusading movement and liberate Jerusalem from the Muslims. He also invited delegates from the Byzantine emperor to the council. Gregory hoped to reunite the Greek and Roman churches, which formally split in 1054. He encouraged the German princes to elect a new Holy Roman emperor because the throne had been vacant since 1250. In 1273, the princes elected Rudolf of Habsburg. Gregory died on Jan. 10, 1276.
