ABSTRACT
The mutual hostility of Christians and Moslems forms one of the leading themes of medieval history. It would be an exaggeration, however, to speak of them as two communities waging a constant war of religion. In the first place, Christendom was not a united body, either politically or ecclesiastically, and the divisions in the Moslem world were equally distinct. Moreover, while Christians and Moslems disputed large areas of Europe, of Asia, and of North Africa, it was the desire for territorial conquest or reconquest that motived the struggle. Religious animosity, indeed, added to the bitterness of the contest; and the sense of a common religion gave a feeling of unity to Christendom on the one hand and to Islam on the other which would otherwise have been lacking. But the idea of a united Christendom was never transformed into a political reality; it remained a sentiment, like the idea of a united Hellas in the days of the Greek city-states.
