Pope Boniface VIII (r. 1294 – 1303) was elected pope after the resignation of Pope Celestine V in December 1294. An amusing disagreement the pope had with Dante Alighieri was over the Divine Comedy. Dante had placed the pope in the eighth circle of hell along with those who had committed simony (see this article). The pope was outraged, but Dante refused to change the text!
Boniface is best remembered for his conflict with the arrogant King Philip IV of France (also known as Philip the Fair–not due to his fairness but because of his apparent good looks). This conflict began in 1296 because the king, wanting revenue for war, taxed the French clergy without first getting permission from the Pope. However, the true cause of this conflict, and many others to come, was that the secular rulers were gaining too much power over the Church and the popes wanted to prevent this.
When Philip taxed the clergy, Pope Boniface wrote a decree called Clericis Laicos, which stated that all who paid the tax would be excommunicated and deposed from office. When the king struck back by arresting a bishop without giving him a fair trial, the pope backed down for a time. He wrote a private letter to the king urging the release of the bishop. It was called Ausculta Fili (‘listen son’). But the French nobles burnt the letter.
Finally in 1303 there was a final confrontation between the two rulers, one secular, the other ecclesiastical. One month later the pope died. This confrontation would be replayed over and over again in the years to come as the monarchs gained religious power and the popes tried to refute it.