Being chosen as mediator, in 1298, by the Kings of France and England in a war which pressed heavily on both, the decree of arbitration which he pronounced, favorable rather to Philip than to Edward I., had been accepted by both of them; and the pope, on laying his injunctions upon them with some severity of language, had exhibited authority in a manner salutary for both kingdoms.

Everything seemed at that time to smile on Boniface, and to invite him to believe himself the real sovereign of Christendom.
An opportunity for a splendid confirmation of his universal supremacy in the Christian world came to tempt him.

A quarrel had arisen between Philip and the Archbishop of Narbonne on the subject of certain dues claimed by both in that great diocese.

Boniface was loud in his advocacy of the archbishop against the officers of the king: "If, my son, thou tolerate such enterprises against the Churches of thy kingdom," he wrote to Philip (on the 18th of July, 1300), "thou mayest thereafter have reasonable fear lest God, the author of judgments and the King of kings, exact vengeance for it; and assuredly His vicar will not, in the long run, keep silence.

Though he wait a while patiently, in order not to close the door to compassion, there will be full need at last that he rouse himself for the punishment of the wicked and the glory of the good." Nor did Boniface content himself with writing: he sent to Paris, to support his words, Bernard de Saisset, whom he, on his own authority, had just appointed Bishop of Pamiers.