Ten things
people get wrong
about the Kingdom of Jerusalem.

The Crusades involved much fighting between Christian and Muslim armies and were preached, on the European side, in straightforwardly religious terms. They also involved: the Frankish armies of the kingdom allied with Muslim states (Damascus, Aleppo, the Ismailis) against other Muslim states; substantial Christian-on-Christian violence (the Fourth Crusade sacked Christian Constantinople; the suppression of the Templars in 1307 was a Catholic-on-Catholic operation; many minor episodes of Crusader-on-Eastern-Christian violence); the perfectly normal political and commercial relations between the Crusader states and their Muslim neighbours throughout most of the kingdom's existence (the Italian maritime republics traded happily with both sides); and the long Frankish settler population that intermarried with the indigenous Eastern Christian population and adopted local food, language, and clothing. The strict religious-war framing is the framing of the medieval European preaching of the Crusades, not the description of how the Crusader states actually functioned.

Salah ad-Din Yusuf ibn Ayyub was a Kurd, born around 1137 in Tikrit in modern Iraq into a Kurdish military family that had served the Zengid rulers of Mosul. His native language was Kurdish; he became fluent in Arabic and Persian as the working languages of his profession. The dynasty he founded — the Ayyubids — was Kurdish in origin and largely Kurdish in its military command, although it employed Arabic as its administrative language. The folk identification of Saladin as a "great Arab leader" is widely encountered in modern Middle Eastern public discourse but is, on the historical record, incorrect. Saladin is a Kurdish national hero, claimed (with some justice) by both Iraqi and Syrian Kurds today.

The medieval Order of the Knights Templar was suppressed by Pope Clement V at the Council of Vienne in March 1312; its property in most of Europe was transferred to the Hospitallers, its last grand master Jacques de Molay was burned at the stake in Paris in March 1314, and the order ceased to exist as a corporate entity. The various modern organisations that style themselves "Knights Templar" — Masonic chivalric degrees, Catholic fraternal orders, romantic-era reconstructions — have no historical or institutional continuity with the medieval order. The genuine institutional descendant of one branch of the order's property is the Portuguese Order of Christ, founded in 1319 by King Denis of Portugal to take over the Templar property and personnel in his kingdom; the Order of Christ is still a Portuguese national honour and is the order whose cross Henry the Navigator displayed on his ships.

Sugar production in the Mediterranean basin was, until the Frankish period, almost exclusively conducted in Egypt and the Levant. The Crusader states invested heavily in sugar plantations and refineries; their development of large-scale Mediterranean sugar production was a real innovation, and the products were exported to Europe in commercial quantities for the first time in the twelfth century. Oranges (specifically bitter oranges and citrons), apricots, lemons, and aubergines were already known in southern Europe through Andalusian (Spanish Islamic) and Sicilian channels before the Crusades, but Crusader-era trade increased their diffusion northward. The famous "Crusader introduction of spices" is partly true (the Crusader-era trade in pepper, cinnamon, and ginger from the Indian Ocean did reach Europe through Crusader ports) and partly mythological (most of these spices had been reaching Europe through other routes for centuries).

The standard Western image of the dirty medieval European is largely a Victorian invention. The first-generation Crusaders may indeed have arrived in the East with poor personal hygiene by Mediterranean standards (the relative scarcity of bathhouses in Western Europe versus the Levant is well-documented in contemporary sources). They learned quickly. The Crusader states inherited and continued to operate the Roman-era and Islamic-era public bathhouses (hammams) of every major Levantine city. Twelfth-century Frankish sources — particularly the Arab observer Usama ibn Munqidh, whose memoirs of dealing with Crusader nobility are one of the great Arabic-language sources of the period — record Franks as enthusiastic patrons of the local baths. Usama tells the famous story of a Frankish knight who took offence at his wife's modest behaviour at the bath. The Franks bathed. Western Europe was the outlier.

The kingdom's Muslim population was not granted formal religious equality and was subjected to legal disabilities (a higher tax burden, no right to bear arms, exclusion from royal courts). Muslim worship in the major Crusader-occupied cities was substantially restricted: the al-Aqsa Mosque was used as a Christian church and the royal palace; the Dome of the Rock was converted to a Christian sanctuary; most major mosques in the cities were converted to churches. In the countryside, however, Muslim rural communities were generally permitted to continue their normal religious life under the supervision of their local Frankish lords, who collected taxes from them on broadly Islamic-era models. The arrangement was a working colonial accommodation, not a multicultural utopia. The most-cited Arab source for the everyday relationship — Usama ibn Munqidh — gives a picture in which casual contact between Franks and Muslims was easy and frequent, but in which the Franks were always in a position of structural advantage.

The Fourth Crusade of 1202-1204 — a Venetian-diverted expedition that sacked Constantinople and established a Latin Empire there from 1204 to 1261 — caused massive damage to the Byzantine state's fiscal, administrative, and military capacity. The Byzantine empire that recovered Constantinople in 1261 was a much smaller and weaker state than the one that had been sacked in 1204; the Anatolian provinces, the principal long-term revenue base, were progressively lost to the Turks during and after this period. The fall in 1453 had immediate causes (the Ottoman buildup under Mehmed II, the use of the new siege artillery) but was made possible by the structural weakening of the Byzantine state, of which the Fourth Crusade was the most damaging single event. The thesis that "the Crusades caused the fall of Constantinople" is therefore not exactly right (the immediate cause was the Ottomans) but not exactly wrong (the Fourth Crusade made the empire too weak to defend itself two and a half centuries later).

The Crusaders of the First, Second, Third, and Fifth Crusades wore mail armour — the so-called hauberk, a knee-length tunic of interlinked iron rings, with a separate mail coif (hood) for the head, mail mittens, and mail leggings — over a padded cloth garment (the gambeson) and under a fabric surcoat. The total weight was about twelve to fifteen kilograms, distributed over the shoulders. Plate armour — the full-body steel armour familiar from the Hundred Years' War and the Battle of Agincourt — was a fourteenth-century European invention; the medieval Levant never saw it on a Crusader. The Crusaders looked, in a phrase, much more like the Bayeux Tapestry than like a suit of fifteenth-century jousting armour.

Outremer is Old French for "overseas" — literally outre-mer, beyond the sea — and was the standard term used by the medieval Franks to refer collectively to all four Crusader states (the kingdom plus the principality of Antioch and the counties of Edessa and Tripoli), as well as more loosely to all Frankish settlements in the eastern Mediterranean. Using "Outremer" to mean only the Kingdom of Jerusalem is a recent imprecision. (This volume uses the term loosely in the same way, knowingly.)

The European elite did, by the late thirteenth century, lose much of its enthusiasm for new crusading expeditions, partly because of disappointment at the failures of previous crusades (especially Louis IX's Seventh and Eighth Crusades), partly because of competing European concerns (Philip IV's wars, the rise of national kingdoms), and partly because the secular and ecclesiastical machinery for preaching and financing crusades had decayed. The Crusader states themselves, however, fell to the Mamluks for direct military reasons: the Mamluks had a vastly superior army, a unified political base, and a strategic geography that made each successive Frankish position untenable in turn. Even substantial European intervention in the 1280s (as proposed by various popes and several monarchs) would not, on the military analysis, have saved the kingdom unless it had been on a scale of the Third Crusade or larger; no Western European monarch was both willing and able to provide such an army in the relevant decade. The fall was a strategic catastrophe with multiple causes, not a simple failure of European resolve.