orig. Tebaldo Visconti
born с 1210, Piacenza, Lombardy [Italy]
died Jan. 10, 1276, Arezzo, Tuscany
Pope (1271–76).
He kept the Holy Roman Empire from disintegrating, by securing the election of Rudolf I as emperor. Rudolf in return promised to lead a new Crusade and renounced claims in Rome and the papal territories. In 1274 Gregory issued a new constitution reforming the assembly of cardinals that elects a new pope. He also initiated a Crusade and worked to unify the Greek and Roman churches. He was beatified Sept. 12, 1713. His feast days are January 28 and February 4.