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.
Heraldry
The origins of heraldry are sometimes associated with the Crusades, a series of military campaigns undertaken by Christian armies from 1096 to 1487, with the goal of reconquering Jerusalem and other former Byzantine territories captured by Muslim forces during the seventh century. While there is no evidence that heraldic art originated in the course of the Crusades, there is no reason to doubt that the gathering of large armies, drawn from across Europe for a united cause, would have encouraged the adoption of armorial bearings as a means of identifying one's commanders in the field, or that it helped disseminate the principles of armory across Europe. At least two distinctive features of heraldry are generally accepted as products of the crusaders: the surcoat, an outer garment worn over the armor to protect the wearer from the heat of the sun, was often decorated with the same devices that appeared on a knight's shield. It is from this garment that the phrase "coat of arms" is derived. Also the lambrequin, or mantling, that depends from the helmet and frames the shield in modern heraldry, began as a practical covering for the helmet and the back of the neck during the Crusades, serving much the same function as the surcoat. Its slashed or scalloped edge, today rendered as billowing flourishes, is thought to have originated from hard wearing in the field, or as a means of deadening a sword blow and perhaps entangling the attacker's weapon.