"Meanwhile, the religious zeal of Christians and Moslems had helped to revive and spread a form of servitude once justified primarily by the ancient laws of war. Members of each faith looked upon the other as infidels, and hence each felt doubly entitled to make slaves of the other when taken as captives. Moors captured in North Africa and in the Spanish peninsula were held in bondage in Italy, Spain, Portugal, and France. Christian prisoners suffered the same fate in the lands of Islam. Christians and Moslems alike believed it just to hold heathens in servitude, and both found victims among the Negroes of Africa. Their operations were facilitated by the fact that slavery already existed among the Negro tribes and that native dealers were often willing participants in the trade in human flesh. The Christian purchasers liked to think of themselves as the agents of civilization and the true religion. The native traders were less philosophical about their business."