The Papacy in the Late Middle Ages
Boniface versus Philip
Whereas Philip was threatened by the strong English king (Edward I), Boniface was threatened by internal enemies, going back to the circumstances of his election as pope. Pope Nicholas IV had died in 1292. The city of Rome was at this time split between two powerful families: the Colonna and the Orsini. The College of Cardinals consisted mainly of Italian prelates and most of these belonged or were under the influence of one or the other of these two families. Between them, they deadlocked negotiations for a new pope.
Two years went by and still no pope had been elected. It was causing something of a scandal among the faithful. Various compromise candidates had been proposed, but none were acceptable until July 1294, when someone suggested a hermit of some note who was living in a cave near Naples. The fellow was old, utterly devout, and clearly could not be regarded as the man of either party. So the cardinals traipsed up the mountain and delivered the good news to the hermit, who was utterly devastated. He did not want the honor, but saw it as his duty, and took the name of Celestine V.
It was a disaster. The man was unfit for the office and within weeks administrative chaos broke out. Humiliated and ashamed, within a year, Celestine resigned his office and returned to his cave, leaving the cardinals back where they'd started. One of the men who had encouraged him to resign was Benedict Gaetani, who was soon after elected pope himself. He took the name of Boniface VIII.
The Gaetani were enemies of the Colonna family, and Boniface immediately set about hounding them out of town and out of their wealth. They were behind many of the plots against him that would come later. Not only they, but others as well, murmured that a pope could not resign and that Boniface's election was therefore invalid. Up in France, as Boniface began making trouble there, King Philip was inclined to agree with that position.
King and Pope quarreled early, in 1296. Over money, of course, but in reality over who would have ultimate control over the clergy in France. Boniface claimed that no cleric was to pay taxes to a king without papal consent. He made this claim in a famous bull, Ad clericos. Philip counteracted this move by issuing a royal edict to the effect that no hard currency was to leave the kingdom without royal permission. Let the clergy pay their papal tithes. The money could not be delivered!
In the face of this, Boniface had to retract. Moreover, other kings objected strenuously to Boniface's claims, and if they all pulled Philip's trick, the papacy would be bankrupt, to the detriment of all Christendom.
Boniface tried again a few years later. This time, feeling even stronger, Philip not only refused to cooperate, he went on the offensive. He took up the claim that the pope had been elected illegally and was no true pope at all (and therefore his demands could be ignored). Even more, Boniface was accused of all sorts of horrible crimes, including murder and heresy. Charges like this had been levelled before, in earlier conflicts between popes and monarchs, but Philip took the controversy to new heights, engaging in a deliberate and widespread propaganda campaign.