1294–1303

Boniface VIII versus Philip IV: the Bull 'Unam Sanctam' and the 'Slap of Anagni'

Pope Boniface VIII crushed the hostile Colonna clan. By the bull Clericis laicos he forbade the clergy to pay taxes to secular rulers without papal permission. In 1300 he proclaimed a jubilee year with full remission of sins for pilgrims.

In 1302 Philip IV of France convened the Estates-General with the third estate. The pope then issued the bull Unam Sanctam (1302). It proclaimed the most extreme form of papal supremacy – that submission to the Roman pontiff was necessary for every person's salvation.

On 7 September 1303, on the eve of a new excommunication's proclamation, Philip's envoys Guillaume de Nogaret and Sciarra Colonna seized the pope at Anagni. Boniface was freed by the townspeople but soon died. The episode marked both the peak and the beginning of the decline of medieval papal claims.