When Boniface became pope it was directly after Celestine V resigned because he realized that he unsuitable for the position. It is not confirmed, but there were rumors that Boniface may have played apart in him stepping down. Boniface was not received warmly into his position. The noble Gaetani family was very unhappy with Boniface for he displayed nepotism in the Papal States. The Spiritual Franciscans had greatly favored Celestine for was dedicated to their religious ideals. These parties joined forces and tried to bring back Celestine by stating that the Pope should not be able to abdicate. They also pulled out a number of accusations against Boniface, saying that he was heretic, a simoniac, and that he had tricked Celestine into abdicating.

Boniface faced more opposition when King Philip IV taxed ecclesiastical property and wealth when England and France were preparing to go to war. Previously, a the Fourth Lateran Council Innocent III had decided that secular rulers could not collect taxes from the clergy unless they first got the approval of the pope. Boniface viewed this as a great trespass on his power and issued a bull, Clerics Laicos. This bull decreed no secular ruler could collect war taxes from prelates with the permission of the pope. He emphasized the obligation of the clergy to obey the pope before the king and expressed that lay rulers have no power over ecclesiastical wealth. Boniface is enforcing his ideal of papal monarchy by stating that he has the most authority.
As a response to this bull, Philip decided to assert his power in a more indirect way by restricting the report to Rome from France of valuable metals and any negotiable currency. This was the source of a healthy portion of annual papal revenues and had a strong impact. As a response, Boniface went back on what he had said before about taxing and specified that in the case of an emergency where the King did not have time to ask the pope, the clergy could be taxed. He essentially gave over the power that he had previously claimed to the King. Later, Philip again asserted his power and indirectly struck a blow to Boniface by arresting one of his ambassadors, the bishop of Pampers, Bernard de Saisset. It was said that he was traitorous, heretical and a blasphemer. Philip then violated canon law by giving him a trial where only he was present and the pope was not.