THE REFORMATION WILL BE LED FROM THE ANGLOSPHERE:

Holland, 47, is tall, beaky, resplendently nerdy about history and fantastically quick-brained. Over the decade I have known him a little (the world of classics is small) he has also become steeled to a certain kind of battle. Last year, before the Scottish referendum, he threw himself, with fellow historian Dan Snow, into campaigning for the union, organising an open letter to Scottish voters by English celebrities from Tom Daley to David Attenborough. Whether or not this lovebombing had any effect is moot: it certainly annoyed some, who felt patronised by the notion that their vote on a serious constitutional issue would be swayed by the views of, say, Bobby Charlton. More seriously, though, in 2012, a documentary he made for Channel 4 called Islam: the Untold Story - based on his book In the Shadow of the Sword - provoked huge controversy. (The book itself was largely received very well.) The documentary looked at the origins of Islam from a strictly historical perspective, and expressed certain ideas - that Islam may not have originated near Mecca, that there was a lack of Muslim historical evidence relating to the origins of the religion, and that little was known about the circumstances of the Qur'an's composition - that sparked 1,200 complaints to Channel 4 and Ofcom.

Meanwhile, Holland was immersed in the mother of all Twitter storms. "Well, what I was really nervous about was less that someone would come and cut my head off than I would lose caste with fellow liberals - that people would think I was racist. So I went on Twitter to rebut accusations that I had got things wrong in the book, but also to square up to people saying, 'You are doing this because you are racist.' The problem with doing that meant that anyone could send me abusive comments or make threats against my family or me." It must, I say, have been frightening and bleak for them (his wife, Sadie, is a midwife, and they have two daughters). "The experience of being in that storm - for a month or so, every day I would get a multitude of threats - was a bit like when you have a bruise on the lip. You feel that it's enormous, and that everyone is looking at you. But if you look in the mirror, you can barely see it. No one really cares. In the eye of that storm, though, it is quite frightening."

Holland's views on Islam, he says, were affected by the violent opinions he encountered online: "Certainly on Twitter there is a disturbing number of Muslims who do think apostates ought to be put to death, and you can see the effect of that in the Middle East, where Isis is not remiss in putting apostates to death. That's the horror of it: one man's apostate is another's liberal Muslim." I suggest that those who believe such things are in a tiny, tiny minority. Holland's point, though, is that there are enough militants using the Qur'an as "the equivalent of a technical manual" for there to be real concern - and real value in applying historical methodologies to early Islamic history. He almost laughs at the surreal notion that late-antique history has become such an explosive force in modern politics and warfare - he recalls arguing about Sasanian law codes and their possible relationship with certain hadiths on Twitter - but of course we both know it is no laughing matter. The day after we speak the director of antiquities at Palmyra, Khaled al-Asaad, is murdered by Isis.

Holland thinks historical inquiry into early Islam can, in the long term, play a part in neutralising violent fundamentalist groups such as Isis - a position he laid out in the Christopher Hitchens lecture this summer at the Hay festival. While I salute Holland's aims as a historian - surely nothing should be out of bounds as a field of historical inquiry - I am, I admit, less certain of this notion. We briefly argue about whether the movement to historicise the events recounted in the Bible in the 19th century actually had much effect on people's faith, which to my mind is governed by factors beyond the rational. And the radicalisation of a minority of Muslims surely cannot be separated from the effects of western foreign policy. Christian fundamentalism, by way of comparison, furthermore seems to me to be a postmodern phenomenon, not something that was tempered by 19th-century rational historical inquiry. He disagrees: the work of scholars such as Albert Schweitzer "changed the terms of argument in the west: Christians do not take the Old Testament as literally as they did 200 years ago and even creationists accept that evolution is a challenge they have to answer." He becomes animated: "To be honest, I wouldn't care about any of these things were it not for the fact that people are using these [religious] texts to justify the raping of nine-year-old girls."

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