Mohammedanism, shortly after its birth (622), began to threaten Christianity. After having driven the Christian Church from northern Africa, the followers of Islam overthrew the Visigothic power in Spain (711) and then swarmed across the Pyrenees to overrun most of France. The very existence of Christendom was at stake, and the future of Europe hung in the scales and might have been very different, had not Charles Martel with his stalwart Christian knights in the bloody battle of Tours (732) checked the advance of the crescent and forced its adherents to hastily retrace their steps. The califate founded at Cordova (756) continued as a standing menace for more than six centuries. Meanwhile Moslem corsairs scoured the Mediterranean, seized Sicily, and from that vantage point sought to make a conquest of Italy venturing at times to the very gates of Rome.
The contest between the faithful of these two religions, continued for centuries and attained its climax in the crusades. The followers of each faith sought to either conquer or exterminate the other. This form of missionary work was like that employed by Charles the Great against the Saxons and Otto the Great against the Slavs. The repeated assaults of Frankish rulers, Spanish princes, and Norman warriors in Italy were finally successful and Islam was thrust back into Africa, but only to enter Europe by way of Constantinople.
In sharp contrast to these harsh methods, there are not a few instances of devout Christians labouring in love among the followers of the Prophet to save
their souls. Conversions to Christianity were not infrequent in Spain, Italy, Egypt, and the East.[259:1] The Franciscans and Dominicans both laboured heroically among the followers of the Prophet to teach them the higher and better faith.[259:2]
Notwithstanding the fact that Christianity spread so rapidly throughout the Roman Empire, yet it must be remembered that more than twelve centuries were to circle away before the cross was carried to all European peoples and planted among them. The problem was as difficult as that encountered to-day in Africa, Asia, and the islands of the seas. By the twelfth century all Europe, except Lapland and Lithuania had been won to Christianity. If the number of Christians approximated 30,000,000 at the death of Constantine, the number at the time of Pope Innocent III. in 1200 may have been 200,000,000 who came within the direct or indirect jurisdiction of the Christian Church. The sweeping control of the Roman Church gathered under her broad ægis possibly 100,200,000. Through these missionary activities, therefore, the successor of St. Peter had extended his actual sway until it included all of western and central Europe with a population as large as that of the Empire of Cæsar at the birth of Christ.
This unprecedented increase in dominion and subjects carried with it a corresponding change in the power, duties, wealth, and opportunity of the Papacy. The Pope of Rome became the greatest force in the West and one of the greatest in the world. The
hierarchy was necessarily extended and elaborated. The number of officers, both locally and in the ecclesiastical court at Rome, was greatly increased. The rapid addition of so many sturdy recruits to the Roman Church, carried on for centuries, gave the Western Church a pronounced ascendency over the Eastern Church. Papal prerogatives, which were little more than assertions in the early period, became realities. As a result of these heroic and persistent missionary efforts, the mediæval Church, at the end of the missionary period, had attained its highest power.
A stream is coloured and influenced in its purity by the soil and rock through which it flows. An institution is modified by the peoples through whom it passes. It is not a matter of surprise to the historical student, in consequence, to see the Christian Church reflecting the civilisation through which it grew. Christianity may easily be reduced to the fundamental Gospel principles taught by Jesus, but in that pure, simple form it was not spread over the world and perpetuated. Originating on Jewish soil, it never outgrew the Jewish tinge. During the post-apostolic period it was powerfully modified by the classical philosophy of Rome, Greece, and Alexandria. In post-Constantinian times the multitudes of heathen converted to Christianity introduced heathen modifications and compromises. The spread of the Church to Teutonic soil, there to encounter a sturdy barbarism in most intimate relations, produced modifying influences which can easily be seen in the history of the Church. The Germanic contribution was to prove to be one of the most important and influential forces in the whole history of the Church, because it created, in
a large sense, modern civilisation and the modern Church.
This period of zealous missionary endeavour among the Celtic and Teutonic tribes was a great pioneer movement. Far too little attention has been paid to it by historians and, consequently, comparatively small credit has been granted to it as a force in the evolution of our institutions to-day. It is impossible to conceive what would have been the history of Europe and the civilisation she has planted around the earth had not Christianity entered at this epoch to lay the foundations. Every institution would have developed differently and the world would certainly not be what it is to-day.