CROSSED, a Tale of the Fourth Crusade. By Nicole Galland. Harper Paperbacks, New York, N.Y. 2008. 641 pages. $15.95 softcover.

Blending history with humor is a great way to communicate and Vineyard native Nicole Galland achieves this tender mix in her latest novel, Crossed, A Tale of the Fourth Crusade, in which she brings to life a disastrous medieval holy war.

The fourth crusade began in the year 1202 as a mission by the pope to rescue the Holy City of Jerusalem from Muslim rule. It never happened. Self-interested crusade leaders diverted the troops and Christians ended up killing and pillaging fellow Christians.

Ms. Galland doesn’t paint the classic picture of knights in shining armor: “. . . ten thousand unwashed soldiers and their unwashed squires, whores, cooks, priests, horses, heralds, armorers, and smiths . . . called themselves pilgrims . . . This meant they were going to an unknown desert, to wrest an unknown city from its unknown inhabitants.”

The story is told largely from the viewpoint of a suicidal vagabond known only as the Briton. A pious knight named Gregor witnesses the Briton’s failed attempt at a murder/suicide and takes him captive to save his soul because “from what I’ve seen you are a sinner, not a criminal, and the burden of a sinner is to repent.”

Repentance, however, is not on the Briton’s agenda, and the realization that he is a captive pales beside his disappointment at still being alive. “I was still dazed, as if I’d been half woken from a deep sleep and wanted nothing but to return to slumber permanently.”

Surly, cynical and bored, the Briton manages to rescue a mysterious Arab princess named Jamilla. Returning her to safety — and exposing the moral failings of the holy war leaders — compels him, grudgingly, to put suicide on the back burner.

Part of the tale is told through the journal of Gregor who vows to “help record the radiant glories of our undertakings in the name of Jesus Christ the Son of God Amen.”

Jamilla, like the Briton, questions the entire cause. I find it strange, she says, “that you are going to kill people to promote Christian doctrine — I don’t recall where Christ asked anyone to do that.”

The fourth crusade was an unequivocal disaster and in Crossed even Gregor slowly comes around: “We are now the only pilgrim army in history to have been excommunicated by the very pope in whose name we set out.”

In an afterword, Ms. Galland points out the parallels between the fourth crusade and contemporary events: “A western military coalition invites itself to liberate a rich eastern land from a usurping tyrant, then finds itself an occupying force fighting insurrectionists.”

It’s no small feat to bring a 13th century military debacle to life, make it relevant in this busy world, and do so with humor and intelligence. Crossed succeeds in doing so.

Nicole Galland will discuss and sign copies of Crossed: A Tale of the Fourth Crusade, next Friday, May 9, at 7:30 p.m. at the Bunch of Grapes Bookstore on Main street in Vineyard Haven.