Pope Gregory X declared his election void.

Pope Gregory X: Pope from 1271 to 1276.

He was named a Cardinal by Pope Gregory X in 1578.

Pope Gregory X, a non-cardinal away on the Crusades, was finally elected.

He was made a Cardinal by Pope Gregory X in 1273.

Pope Gregory X (1271-1276) create five cardinals in one consistory.

Pope Gregory X approved all 31 chapters, after modifying some of them, thus clearly indicating papal prerogatives.

In the right aisle is the funerary monument of Pope Gregory X (died 1276), dating to the early 14th century.

Pope Gregory X died on January 10, 1276, at Arezzo.

He personal physician to Pope Gregory X and later became archbishop and cardinal.