Thanks to the teaching of the Church, a large proportion
of the border wars were converted into Crusades for the propagation of the
faith or the extermination of the unbeliever or the defence of holy places.
Often enough the religious motive was introduced as an afterthought, and gave a
thin veil of respectability to operations which it would otherwise have been
difficult to excuse. In some cases, however, those who enlisted as the soldiers
of the Church were sacrificing their material interests for the good, as they
supposed, of their own souls and the Christian commonwealth. There was nothing
essentially Christian in this spirit of self-devotion; it had long been
epidemic in the Mohammedan world, and accounts for the most successful
encroachments of Islam upon Europe and the Eastern Empire. The impulse affected
Western Christendom for a relatively short period of time, only once or twice
producing movements at all commensurable with those which had emanated from Arabia,
Asia Minor, and Africa, and leading to no conquests that can rank in magnitude
with the caliphates of Bagdad, Cordova, and Cairo. But the Christian Crusade is
in one sense more remarkable than the Mohammedan Jehad.
Western Europe had long
ago emerged from the nomadic stage, and even the ruling classes of Western
Christendom, cosmopolitan as they may seem to us, were attached to their native
soil by many ties. If the upheaval was smaller in the West than in the East,
the material to be set in motion was more stubborn and inert, the prizes to be
held before the eyes of the believer were more impalpable and dubious. There were
ventures near at hand for which the Church could find volunteers without the
slightest difficulty. But those which she was more particularly bent on
forwarding were distant, hazardous, and irksome; the majority of the men who
went on her great Crusades had no prospect of any temporal advantage. In the
end those enterprises to which she gave her special countenance proved the
least successful. It was not in the Eastern Mediterranean but in Spain, in
Lower Italy, and in Central Europe, that the frontiers of Western Christendom
were permanently advanced. For the historian, however, the failures have an
interest not inferior to that of the more productive enterprises.