Military history of the Crusader states
The Seljuk–Crusader War began when the First Crusade wrested territory from the Seljuk Turks during the Siege of Nicaea in 1097 and lasted until 1128 when Zengi became atabeg of Aleppo. At the latter date, the chief threat to the Crusaders from the east and north became the Zengids. The conflict was generally fought between European Crusaders and the Seljuk Turks and their vassals. The Muslim Syrian emirates occasionally allied themselves with the Christians against rival states.
Historiography of the Crusades
The historiography of the crusades has been a controversial topic since at least the Protestant Reformation.
The term "croisades" was first used to refer to the entire period from the First Crusade until the fall of the Kingdom of Jerusalem in French historiography of the 17th century.
The 18th-century Enlightenment ideology as represented by Edward Gibbon and Voltaire held up the crusades as an example of medieval barbarism, while 19th-century Romantic nationalism tended to paint them in a heroic light, surrounding the crusades with an aura of romance and grandeur, of chivalry and courage. In the second half of the 20th century, western historiography again tended to be more critical of the crusades, following Steven Runciman (1951–4).
Popular opinion, influenced by general trends of decolonisation and critical theory tended to portray the crusades with a sense of "western guilt".
In early 21st literature, a "pluralist" view has become common which tends to generalize the concept of the crusades
to include other medieval military campaigns authorized by the church, such as the Northern Crusades, the Albigensian Crusade or the Reconquista.