The embattled citadel of Jerusalem, like the Holy Grail, was pictured as being situated outside the world. _There_ the longing which had become so vast that it had outgrown the earth, would be stilled. A direct way must lead from Jerusalem, the centre of the earth--it still takes this position in Dante's _Divine Comedy_--to Paradise. Was it not the spot where the Cross of the Saviour had been raised? Had not once before heaven opened above the city to receive His risen body? Was it not the scene of countless miracles in the past? Why should it be different now? Men knew practically nothing of Palestine; they had in their minds a fantastic picture tallying, in every respect, with Biblical accounts; doubtless, the footprints of the Redeemer could easily be traced everywhere; the possession of the country promised the fulfilment of transcendental dreams.
The impulse and the strength necessary for the organisation of the Crusades were spiritual phenomena inherently foreign and even hostile to the Church; but thanks to the mental superiority of the popes of that period, and the overpowering conception of a divine kingdom, they became the instruments of the greatest triumphs vouchsafed to the Church of Rome. The hosts, driven across the sea by inner restlessness and ill-defined longing, in reality fought for the aggrandisement of the Church. The great Hildebrand resolved to lead all Christendom to Jerusalem, to found on the site of the Holy Sepulchre the divine kingdom preached by St. Augustine, and invest--a risen Christ--the emperor and all the kings of the earth with their kingdoms.
The crusader and the knight in quest of the Holy Grail present together a paradoxical combination of the Christian-ecclesiastical and the mundane-chivalric spirit, which is quite in harmony with the spirit of the age. These two worlds, inward strangers, formed--in the Order of the Knight-Templars, for instance--a union which, while possessing all the external symbols of chivalry, attributed to it heterogeneous, ecclesiastical motives; the glory of battle and victory, the caprice of a beautiful damsel, were no longer to become the mainsprings of doughty exploits; henceforth the knight fought solely for the glory of God and the victory of Christianity. In addition to King Arthur's knights, the classical Middle Ages worshipped the ideal of these priestly warriors who waded through streams of blood to kneel humbly at the grave of the Saviour, of those seekers of the Holy Grail who dedicated themselves to a metaphysical task. King Arthur's Round Table served the actual orders of knighthood as a model. Not only the Franciscans of Italy, but also slow, German mystics, such as Suso and the profound Johannes Tauler, delighted in borrowing their similes and metaphors from knighthood. Tauler speaks of the "scarlet knightly robes" which Christ received for His "knightly devotion": "And by His chivalric exploits he won those knightly weapons which he wears before the Father and the angelic knighthood. Therefore Christ exults when His knights elect also to put on such knightly garments ...," etc.