Christendom: The Triumph of a Religion, AD 300-1300
by Peter Heather
Knopf 2023

Peter Heather, chair of medieval history at King’s College, London, opens his hefty, important new book Christendom: The Triumph of a Religion, AD 300-1300 with a declaration of intent: he sees the need to supplant the “triumphalist outline” of typical histories of Christianity with something more striving and contingent. “Fundamentally,” he writes, “it is no longer possible to construct a narrative on the underlying assumption that its victory over all rivals in the dim and distant past is evidence of Christianity’s essential superiority as a religion.” 

It’s important though not debarring to note that this is both a straw man and a straw man constructed of artificial straw. Not only is it very much still possible to construct a narrative assuming the essential superiority of the Christian religion – Heather might not stray into the pertinent section of his bookstore to see it, but there are dozens and dozens of books published every year working on exactly that assumption – but no serious history of Christianity written in at least the last 60 years has proceeded from the kind of triumphalist outline Heather describes. 

Even so, despite spurning a triumphalist outline, he’s certainly describing a kind of triumph in these pages. He fleshes out a narrative that starts after the scrambling and fractious earliest beginnings of Christianity, and that narrative eventually reaches a state of almost mind-boggling power. “A thousand years after Constantine,” Heather writes, “all of Europe was controlled by Christian rulers. Christendom – that part of the world where official Christianity exercised a dominant hold on the totality of the population: lords and commons, rulers and ruled – had come into existence, and that was that.”

The image that gradually emerges is remarkable in its imbalance: it’s the story of a power developing for centuries before it even seemed to think about establishing a power center. It was only in AD 725 that Pope Gregory II successfully defied the power of the Byzantine Empire and set the Church on the path to worldly power. “At this moment, the independent Republic of St. Peter was born,” Heather writes. “It took a few more years for everyone to realize that something momentous had occurred …” As Heather observes, papal religious authority was “an astonishingly late phenomenon” within the European Christian tradition. 

Heather strikes an almost austerely grand narrative tone throughout and carries it off in what grows into a genuinely impressive survey. There are more details than personalities in this telling; between 1308 and 1323, for example, the Inquisition in Toulouse condemned 930 people for heresy but only burned 42 (even so, as Heather points out, “the list of punishments inflicted in the name of a supposedly loving God is horrific”). And although he’s trying to refute a triumphalist narrative at least in terms of post hoc justifications, by the end of his book Heather is nevertheless describing a triumph, with the heads of every Western nation being Christian and paying at least lip service obeisance to the Church. 

It’s no less a fascinating story for having been told many times before, especially when it’s told with this degree of grounding (30 pages of densely-packed notes and an extensive bibliography) and understated eloquence. Its account of a Church superstate that was both pugnacious and surprisingly extemporaneous is likely to set the terms of discussion for all future such accounts.

Steve Donoghue is a founding editor of Open Letters Monthly. His book criticism has appeared in The Washington Post, The American Conservative, The Spectator, The Wall Street Journal, The National, and the Daily Star. He writes regularly for The Boston Globe, the Vineyard Gazette, and the Christian Science Monitor and is the Books editor of Georgia’s Big Canoe News.