With no other country save possibly Italy has the Roman Catholic Church been more closely linked than with Spain. To think Spain was to think Roman Catholicism. Ferdinand and Isabella whom the world remembers best in relation to the discovery of the western world were known as the Catholic kings and their oft expressed motive in the conquest of the new continent was that of extending the holy faith. Mohammedanism with its resistless armies had made heavy inroads upon the Christian world; Luther and his fellow reformers in Germany, France, and Switzerland had wrought still further havoc, separating vast numbers of the faithful from their allegiance to Rome. To Spain and the Spanish monarchs was to belong the glory of restoring, by their zealous conversion of the western peoples, the power and prestige of Rome. In a few short years Spanish conquerors followed by Spanish priests and nuns had planted the cross from Mexico to the southern end of South America.