Doubtless the good knight felt that the altar of his consecration was not high enough. Even his vow to defend the faith had, within the bounds of Christendom, little field where it could be honored by exploit of arms. To take his part in the miserable quarrels that were chronic between rival popes, or in the wars of the imperial against the prelatic powers, both professedly Christian, could not satisfy any really religious desires he may have felt. The chivalric spirit thus kindled the aspiration for an ideal which it could not furnish. If the soldier of the cross must wear armor, he would find no satisfaction unless he sheathed his sword in the flesh of the Infidels, whose hordes were gathering beyond the borders of Christendom. The institution of Chivalry thus prepared the way for the crusades, which afforded a field for all its physical heroism, while at the same time these great movements stimulated and gratified what to this superstitious age was the deepest religious impulse. CHAPTER IV. THE FEUDAL SYSTEM—GENERAL PRINCIPLES—INFLUENCE ON PEOPLE. In accounting for the crusades we must consider the governmental condition of Europe at the time. Under no other system than that of feudalism would it have been possible to unify and mobilize the masses for the great adventure. Had Europe then been dominated by several great rulers, each with a nation at his control, as the case has been in subsequent times, even the popes would have been unable to combine the various forces in any enterprise that was not purely spiritual. Just to the extent in which the separate nationalities have developed their autonomy has the secular influence of the Roman see been lessened. Kings and emperors, whenever they have felt themselves strong enough to do so, have resented the leadership of Rome in matters having temporal bearings. Nor would the mutual jealousies of the rulers themselves have allowed them to unite in any movement for the common glory, since the most urgent calls have never been sufficient to unite them even for the common defence, as is shown by the supineness of Catholic Europe when, in the fifteenth century, the Turks crossed the Marmora and assailed Constantinople.