Gregory X, d. 1276, pope (1271–76), an Italian named Tebaldo Visconti, b. Piacenza; successor of Clement IV. After Clement IV's death the cardinals took 34 months to elect a pope. Gregory was archdeacon of Liège when elected and neither a cardinal nor a priest. At the time he was in the Holy Land. He became a conciliator in European politics and helped to end civil war in Germany by supporting the election of Rudolf of Hapsburg as emperor. He convoked the Second Council of Lyons (1274; see Lyons, Second Council of Lyons, Second Council of, 1274, 14th ecumenical council of the Roman Catholic Church. It was summoned by Pope Gregory X to discuss problems in the Holy Land, to remove the schism of East and West, and to reform the church.
..... Click the link for more information. ) and led in its work, particularly in the temporary reunion with the Orthodox of Constantinople. He was succeeded by Innocent V. Gregory was beatified in 1713.

Gregory X

orig. Tebaldo Visconti

(born c. 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.