Before embarking on my crusader novel, King of the Middle March, I thought I'd go to the Front, as it were - Zadar on the coast of Croatia, which was the scene of one of the most outrageous episodes during the grisly Fourth Crusade, when Christian crusaders laid siege to dissident Christian Zara.
My wife Linda and I spent the morning down in the harbour assaulting the Old Town with ballistae and tormenta and other siege-engines. Returning to our hotel, we passed a tower house vibrating with laughter, shrill cries, blood-curdling yells.
You've guessed it - an elementary school.
Then out of the upper window sailed a paper dart. I chased and caught and opened it. It was decorated with the most painstakingly-coloured heart, pierced by a scarlet arrow.
I suppose I would have found writing this novel shocking at any time, but to do so while Britain and the United States were bombing Iraq was at times almost intolerable. While writing a short chapter in which French thugs grab a defiant boy - a boy not unlike those Palestinian kids who chuck stones at Israeli tanks - and hurl him over the town wall in a giant catapult, I was convulsed by tears. When I told Philip Pullman as much, he said he had done exactly the same at one point while writing His Dark Materials.
So how desirable is it for children's writers to engage with war? Who has done so? And why? For the past three months, I have been snowed in, judging the 2004 Whitbread Children's Book Award. What has struck me is how a great proportion of these books are escapist. In my substantial pile, there were only five books embracing crucial contemporary issues (although if one more blurb-writer tells me a book is "gritty", I will tear my hair out) and a solitary historical novel. The remainder were fantasy fiction.
Just a couple of the "realistic" novels set in the present-day concerned the actuality and aftermath of conflict. It is strange, this, when armed conflict (courtesy of TV, radio and the press) is part of the fabric of our daily lives, even if mercifully few children living in Britain have direct experience of it. Iraq, the Palestinian Territories and Israel, Afghanistan and Sudan - and Ireland, still... It's a dismal litany.
There's fighting aplenty in fantasy fiction, of course, but so much of it is easily won and therefore meretricious, involving causes and characters I find impossible to care about. Who then, in our time, really has written about conflict forcefully, truthfully and compassionately for children?
Many people would put Robert Westall top of their list. Absolutely. But how about Benjamin Zephaniah (Refugee Boy), Beverly Naidoo (Journey to Jo'burg), Bernard Ashley (The Little Soldier) and Theresa Breslin (Remembrance), Robert Swindells (Brother in the Land) and Linda Newbery (The Shell House), Alan Gibbons (The Defender) and our gruff-and-tender children's laureate, Michael Morpurgo (Private Peaceful)? Their books explore the World Wars and also the Irish paramilitaries, racism, conflict in Africa and the Middle East. They are all on my roll of honour.
To my mind, writing about children caught up in war is a way of writing about the important qualities and values that war demands: self-reliance, compassion and loyalty, moral and physical courage, an ability to be a team-player but a refusal to be dumbed down.
When is life more vivid, more precious, than in the presence of death? And when is man or woman more conscious of shared humanity than when facing a mortal enemy?
"I am the enemy you killed, my friend." Wilfred Owen's words, remember?
In King of the Middle March, my young Arthur de Caldicot, exposed to the horrors of the crusade, asks himself questions that simply would not have occurred to him in peacetime. Are the innocent and helpless necessarily caught up in any war? Do both sides always claim God is on their side? Is there such a thing as a just war? Arthur is driven to question the very legitimacy of violence.
These are issues no less bitingly relevant today than they were 800 years ago. The author of a war novel, armed to the teeth, has a god-given opportunity to put tough questions, advocate tolerance and celebrate difference. To flight a love-arrow, in fact.
The concluding part of Kevin Crossley-Holland's Arthurian trilogy, King of the Middle March, is published by Orion and is now in paperback. The shortlist for this year's Whitbread children's book award will be announced on November 10