The origins of the Equestrian Order of the Holy Sepulchre of Jerusalem date back to the First Crusade, when its leader, Godfrey de Bouillon, liberated Jerusalem. As part of his operations to organize the religious, military and public bodies of the territories newly freed from Muslim control, he founded the Order of Canons of the Holy Sepulchre. According to accounts of the Crusades, in 1103 the first King of Jerusalem, Baldwin I, assumed the leadership of this canonical order, and reserved the right for himself and his successors (as agents of the Patriarch of Jerusalem) to appoint Knights to it, should the Patriarch be absent or unable to do so.
The Order’s members included armed knights chosen from the crusader troops for their qualities of valor and dedication; they vowed to obey Augustinian Rule of poverty and obedience and undertook specifically, under the command of the King of Jerusalem, to defend the Holy Sepulchre and the Holy Places.
Very soon after the First Crusade the troops began to return to their homelands. This led to the creation of priories all over Europe, which were part of the Order.
The Order first began to fail as a cohesive military body of knights after Saladin regained Jerusalem in 1182, and completely ceased to exist in that format after the defeat of Acre in 1291. The passing of the Christian Kingdom of Jerusalem left the Order without a leader, though it continued to survive in the European priories thanks to the protection of sovereigns, princes, bishops and the Holy See. The priories kept alive the ideals of the Crusader Knights: propagation of the Faith, defence of the weak, charity towards other human beings. With the exception of events in Spain, it was only rarely that the Knights of the Holy Sepulchre ever took part again in military action to defend Christianity.