“Deus vult!” — God wills it! — was the battle cry of the First Crusade, in which armies of Europe, at the very end of the 11th century, marched off to liberate the holy city of Jerusalem and conquer the infidel Turks, who were then sweeping all before them in Asia Minor.

Whatever God’s actual intentions in the matter, and He is known to move in mysterious ways, His representatives on earth, Pope Urban II in Rome and the Emperor Alexios in Constantinople, quite clearly fostered this great martial enterprise for political purposes of their own. The emperor, assailed by enemies on his frontiers and by rivals within his family, was desperate for military aid, just as the pope was comparably eager for a galvanizing cause that would confirm his primacy as the leader of the Christian world.

Older studies of this complex military venture — merely one in a series of clashes between “Europe” and “Asia” that goes back as far as the Trojan War and continues to this day — often tend to emphasize its romantic character. In this view, Pope Urban’s electrifying call to arms at Clermont in 1095 is regarded as the starting point for years of heroism and self-sacrifice. That day, in a field in France, the pontiff thundered out that that the Muslims, “a foreign people and a people rejected by God, had invaded lands belonging to Christians, destroying them and plundering the local population.” He then proceeded to detail the horrors inflicted by these demonized Turks:

“They throw down altars, after soiling them with their own filth, circumcise Christians, and pour the resulting blood either on the altars or into the baptismal vessels. . . . When they feel like inflicting a truly painful death on some they pierce their navels [and] pull out the end of their intestines. . . . They shoot arrows at others tied to stakes; others again they attack having stretched out their necks, unsheathing their swords to see if they can manage to hack off their heads with one blow. And what can I say about the appalling treatment of women, which is better to pass over in silence than to spell out in detail?”

Given such atrocities, how could any respectable Christian warrior hesitate to act? As it happens, Urban’s oratory hardly exaggerated the Turkish ruthlessness, although very soon the Crusaders would slaughter with a comparable barbarity.

‘The First Crusade: The Call from the East’ by Peter Frankopan (Belknap/Harvard Univ. 262 pp. $29.95) (Belknap Press)

The subtitle of Peter Frankopan’s highly readable “The First Crusade: The Call From the East” — underscores his revisionist approach to his subject: He seeks to understand the roots of the Crusades in the literally Byzantine politics of Asia Minor during the late 11th century, focusing especially on the empire’s strategic accommodations with its enemies in the aftermath of an ignominious defeat at the battle of Manzikert in 1071. The book’s hero is, in effect, the Emperor Alexios I. Komnenos, who spent his reign in a relentless quest for stability.

In some instances, Alexios triumphed on the battlefield, as when in 1091, at Lebounion, he essentially wiped out the marauding Pecheneg nomads. But more often he preferred high-level diplomacy, either co-opting or buying the friendship of various Muslim warlords, although such ententes lasted only until those leaders were killed or died. Eventually, Alexios’s enemies grew too powerful to be placated. In short order, his dominion over the seaboard and interior of Asia Minor essentially collapsed. There was a coup attempt involving close associates, including his brother. The empire was tottering.

But the West possessed fighting men and modern technology — chiefly the knight mounted on an armored war horse — and there might lie salvation, of a sort. By eliding the interests of Constantinople with the promise of liberating Jerusalem, Alexios presented himself as a champion of Christendom. He wrote to Urban, who, faced with a rival pope and widespread clerical discord, quickly grasped that a noble cause in a distant land would bolster his wobbly perch on the throne of St. Peter. To increase the Crusade’s attractiveness, the savvy pontiff emphasized not only the spiritual rewards of participation, but also the virtual guarantee of a place in heaven for those who lost their lives. The leaders of the Crusade soon included Robert, Duke of Normandy (one of William the Conqueror’s sons); Count Raymond of Toulouse; Godfrey of Bouillon; and the soon-to-be-famous Bohemond, whose family controlled the Norman kingdom of Sicily. They and their carefully recruited armies, consisting of reliable fighting men, would meet at Constantinople in 1096 and 1097.

In the meantime, the unexpected occurred. From 1095 to ’96, a charismatic preacher, Peter the Hermit, gathered a following of his own and, without papal authorization, unleashed what is now known as the People’s Crusade. Whipped to a frenzy, this ragtag and chaotic mob moved across Europe, preaching anti-Semitism, murdering Jewish populations and devastating the countryside in its hunger for food and supplies. Somehow, a remnant of these marauding zealots made their way to Asia Minor, where they brutally overran a small castle near Nicaea — and were in their turn crushed by vengeful Turkish forces. Ironically, many of these fanatical Christians quickly converted to Islam to save their miserable lives.

For Alexios this unofficial People’s Crusade presaged the difficulty he would find in trying to control the armies and ambitions of Bohemond, Godfrey, Raymond and the other Western leaders. But, despite near catastrophe time and again, the Crusaders triumphed: They assailed the heavily fortified Nicaea until the emperor eventually brokered a truce. The city of Antioch fell, after months of siege and the death of thousands of Crusaders and the desertion of many others. Frankoban’s penultimate chapter — “The Crusade Unravels” — provides a detailed account of the taking of Jerusalem and the establishment of Godfrey of Bouillon as its new king. He reigned for just under a year, dying in summer 1100.

In the years to come, Bohemond — named Prince of Antioch — emerged as the Crusade’s best-known hero, his exploits chronicled in the “Gesta Francorum,” or “The Deeds of the Franks.” Emperor Alexios, by contrast, quickly drew down the vilification of the squabbling Crusaders, being perceived as villainous and hypocritical. Bohemond even went so far as to organize a new “crusade” to attack Constantinople and oust the emperor. He failed entirely, although his reputation as a parfit gentil knight was not tainted. Instead, the emperor’s daughter Anna Komnene tried to rehabilitate her father in her notable, if often unreliable, history “The Alexiad.”

That work of rehabilitation is furthered in this carefully researched book. As Frankopan states resoundingly in his last paragraph, “Alexios I Komnenos put in motion the chain of events that introduced the Crusades to the world,” and it was his “call from the east” that reshaped the medieval world. Certainly, “The First Crusade” tells a complex story, but its presentation of political machinations, compromises and betrayals seems utterly convincing. The harsh truths of realpolitik are, alas, with us always.


Dirda reviews each Thursday in Style and conducts a book discussion for The Washington Post at wapo.st/reading-room.


The Call From the East

By Peter Frankopan

Belknap/Harvard Univ. 262 pp. $29.95