Rather than catalogue all of the historical inaccuracies in this movie (and they are legion) I will confine myself to two general threads of anachronism that are woven throughout. First, the Kingdom of Jerusalem is frequently referred to in this film as a “new world.” It was nothing of the sort. Indeed, it was the oldest of the Old World. To watch this movie one would think that the Holy Land was a recently-discovered virgin wilderness just waiting for colonization by strapping young blacksmiths. Balian even sets up his own plantation, thus introducing irrigation to the Fertile Crescent. The Holy Land that Scott and Monahan describe clearly owes much more to post-medieval British history, where overseas lands of opportunity like North America, Australia, and India offered a fresh start for those seeking a new life.
The second major anachronism is the movie’s approach to religion. Most people know that the Crusades were wars of faith. Crusaders underwent extreme hardship, risking their lives and expending enormous amounts of money because of their devotion to Christ, his Church, and his people. Crusader piety also manifested itself in extraordinary devotion to the Virgin Mary and the saints, particularly those saints who had lived in the Holy Land. The Kingdom of Heaven, however, performs the delicate operation of stripping religious piety completely out of the Crusades. Balian and his father appear to be agnostics. Other Crusaders, like the Hospitaller, are openly critical of religion. Indeed, all of the good guys in this movie seem to have no devotion to God at all, only a devotion to tolerance. The bad guys, on the other hand, are all religiously devout, which causes them to be either evil (like Guy and Reynald) or mad (like the glassy-eyed preacher who chants, “To kill a Muslim is not murder, it is the path to heaven”). In other words, the medieval world is portrayed in much the same way that Hollywood views America: Smart people either have no religion or do not take it very seriously. The rest are right-wing Christian fanatics.
There are no churches in this movie, not even in the holiest of cities. There are no monks, no nuns, and very few pilgrims, all of whom would have filled the streets of medieval Jerusalem. Only two priests appear in the film, one a twisted corpse mutilator and the other a villain whose strategy for defending Jerusalem is to convert to Islam and leave the people to die. Scott scatters a few crosses here and there, but there are no crucifixes, which were much more common in the Middle Ages. Beautiful set decoration of Crusader palaces includes no icons of Mary or the saints, indeed no religious art of any kind. Christians, Muslims, and Jews all live in harmony in this cinematic Jerusalem. Yet, in truth non-Christians were forbidden to live in the Holy City during the reign of Baldwin IV. But it is not just Christianity that Scott sterilizes. Muslims are shown praying a few times in the film, yet the only devout Muslim is a black-robed cleric demanding that Saladin attack the Christians and capture Jerusalem. The message here is clear: Religion leads to fanaticism, and fanaticism leads to war.
As a matter of plot logic, one might reasonably wonder why all of these Crusaders wearing crosses on their breasts and marching off to hopeless battles care so little for Christianity? When preparing for the defense of Jerusalem, Balian proclaims that it is not the stones that matter, but the people living in the city. In order to save the people’s lives he threatens to destroy all of the Christian and Muslim holy sites, “everything,” he says, “that drives men mad.” Yet if he is only concerned with defending people, why has Balian come all the way to Jerusalem to do it? Aren’t there plenty of people in France who need defending? The truth is that Scott’s Balian has it exactly wrong. It is the stones, the buildings, the city that mattered above all else. Medieval Christians saw Jerusalem as a precious relic sanctified by the life, death, and resurrection of Christ. The people were there to glorify God and defend His Holy City. The real Balian, faced with the inevitable conquest of Jerusalem, threatened to destroy the Dome of the Rock if Saladin did not abandon his plan to massacre the Christian inhabitants. That plan is airbrushed out of the movie. Indeed, the good and noble Saladin of this movie lets all of the citizens depart with a hearty, good-natured smile on his face. The real Saladin required them to pay a ransom. Those that could not — and there were thousands — were sold into slavery.