Pope Boniface VIII

Pope Boniface VIII (c. 1235 – 1303), born Benedetto Caetani, was Pope from 1294 to 1303. Today, Boniface VIII is probably best remembered for his feuds with Dante, who placed him in a circle of Hell in his Divine Comedy, and with the English and French kings. He was also the first pope to wear the zucchetto, a small skullcap that covers the tonsure.
In 1296 Pope Boniface VIII issued Clericis Laicos, which threatened excommunication for any lay ruler who taxed the clergy and any clergyman who paid the taxes. Despite being pious himself, the King of England, Edward 1st, retorted by decreeing if the clergy did not pay, they would be stripped of all legal protection and the King’s sheriff would seize their properties. The Pope backed down.
His bull of 1302 Unam sanctam, asserting papal authority over all temporal rulers was just as controversial and King Philip IV of France responded with a counter attack and was behind the kidnapping of the pope by some Italian noblemen. The Pope was soon released but so roughly was he treated that Boniface died shortly afterwards.