The monastic Knights Hospitaller order was created following the First Crusade by Blessed Gerard de Martigues whose role as founder was confirmed by the papal bull Pie postulatio voluntatis issued by Pope Paschal II in 1113.Gerard acquired territory and revenues for his order throughout the Kingdom of Jerusalem and beyond. Under his successor, Raymond du Puy, the original hospice was expanded to an infirmarynear the Church of the Holy Sepulchre in Jerusalem. Initially, the group cared for pilgrims in Jerusalem, but the order soon extended to provide pilgrims with an armed escort before eventually becoming a significant military force. Thus the Order of St. John imperceptibly became militaristic without losing its charitable character.

Raymond du Puy, who succeeded Gerard as Master of the Hospital in 1118, organized a militia from the order's members, dividing the order into three ranks: knights, men at arms, and chaplains. Raymond offered the service of his armed troops to Baldwin II of Jerusalem, and the order from this time participated in the crusades as a military order, in particular distinguishing itself in the Siege of Ascalon of 1153. In 1130, Pope Innocent II gave the order its coat of arms, a silver cross in a field of red (gueulles).