The War Against Heresy in Medieval Europe
By R. I. Moore, University of Newcastle
Lecture given at the University of Pennsylvania (2003)
Introduction: ‘There must be heresies’, St Paul had said, and in the early Christian centuries, as everybody knew, a multitude of heresies had repeatedly torn the church apart so that its survival as a unified body had been seriously in doubt. The greatest writings of the greatest Fathers – St Augustine especially – had been composed in the struggle against them, to define Christian teaching for all time, and to caution their successors against errors associated with the names of Pelagius and Donatus, Mani and Arius, and a host of others. Catholics continued to regard heresy as a menace to the church. But by the tenth century, and for some centuries before, there was no lively apprehension that heresy was widely disseminated in the world, or that the faith was actually endangered by it. No surviving writer suggested on the eve of the millennium that the propagation of heresy of heresy among the people of Western Europe was active, or that any of the heresies of antiquity had survived. There were occasional references to heresy as a theological danger, but that is all.
This changed quite suddenly in the early part of the eleventh century. Ademar of Chabannes, writing in the 1020s and ’30s, is the first substantial author who clearly believed that heretics were active in his lifetime. His voluminous writings, still being searched, bear ample testimony to that. Several of his contemporaries agreed with him, including King Robert I of France, who burned about fourteen people – different numbers are given by the sources – both men and women, at Orleans in 1022, the first since antiquity to meet this fate. They were followed by an unknown, but not small number at Milan in 1028, and another group, again of unknown size, was hanged on the orders of Emperor Henry III at Goslar in 1052. There are grounds for suspecting, though no warrant in the sources for positively affirming, that these were not the only people who met violent deaths as suspected heretics, and with greater or lesser degrees of formality, in those decades, which also saw other accusations of spreading heresy, some of which we shall have to look at more closely.