Towards the end of the thirteenth century it gradually became clear that the hierocratic aspirations of the popes would finally have to give way to a new type of caesaropapism, the formation of what has been called ‘national churches’, on which kings or other secular rulers had a strong hold. The history of the years around 1300 teaches us that the pope in Rome had not properly understood the signs of the times. We are indebted to his misunderstanding for some of the most fascinating politico-ideological documents of the Middle Ages, as the final act of the struggle between emperor and pope and between pope and French king was played out to the accompaniment of an unprecedented polemic barrage. The starting signal came in 1294 when Pope Celestine V abdicated after a pontificate of barely five months; the contest ended with the death of Emperor Louis in 1347.