The thirteenth century was a period of mixed fortunes for the west in its wars against the Muslims and other enemies of the Church. In Spain, for example, Christian victory at the battle of Las Navas de Tolosa in 1212 was recognised by contemporaries as a turning point in the Reconquista. Cordoba was captured by Ferdinand III of Castile in 1236 and Seville surrendered in 1248. The conquest of Greece by the Fourth Crusade in 1204 established the Latin Empire of Constantinople; it was lost in 1261. Elsewhere, crusading continued in the Baltic; it enjoyed a modicum of success against the heretics in Languedoc; and it was used, on occasion, by the papacy against its political opponents.

Despite this wide range of activities, the defence of the Latin Kingdom of Jerusalem remained, in the context of the Holy War, the single most important area of conflict. The loss of the Holy Land in 1291 therefore had a profound impact on Christendom. The reactions of contemporary writers to the fall of Acre varied from reasoned criticism to eschatological hysteria. But the need for such writers to explain the event, the shock which the event created and the fact that the loss was generally regarded as a temporary one suggest that perhaps the most widespread feeling was one of surprise.

This study, however, has shown that the fall of Acre, whilst of major significance since it marked the end of Latin rule in the area, cannot be regarded as unexpected. Rather, it was the inevitable outcome of a period of forty years during which the Latin East, largely unsupported by the western states which had established, and then helped to re-create, the Latin Kingdom of Jerusalem, had been opposed by the united threat of the Muslim states in the region. Most of the damage had, in fact, been done by the end of the 1260s; only a few sites, mainly on the coast, were able to survive until the end.

The chronic lack of manpower from which the Latin states suffered, relative to their Muslim neighbours, was apparent in every aspect of the military history of this period and had a profound effect on Christian strategy.