KING CHARLES AND KING FRANCIS. About the time Cortes conquered Mexico, his master, King Charles of Spain, began a war against Francis, the king of France. As long as these two kings lived they were either fighting or preparing to fight. Had Charles been king of Spain only, there might have been no trouble, but he ruled lands in Italy and claimed others which the French king ruled. He also ruled all the region north of France which is now Belgium and Holland, and he owned a district which forms part of eastern France near Switzerland. As he was the German emperor besides, the French king thought him too dangerous to be left in peace. These wars have little to do with American history, except that they helped to weaken the king of Spain and to prevent the Spaniards from making the most of their early successes in colonizing. RELIGION A CAUSE OF STRIFE. Religion was the most serious cause of quarrel in the sixteenth century, and the king of Spain was the prince most injured by the struggle. At the time of Prince Henry of Portugal and of Columbus all peoples in western Europe worshiped in the same manner, taught their children the same beliefs, and in religious matters they all obeyed the pope. But by 1521 this had changed. The troubles began in Germany when Charles V was emperor. Before they were over Philip II, son of Charles, lost control of the Dutch, who rebelled and founded a republic of their own. The English finally became the principal enemies of Spain. The French, most of whom were of the same religion as the Spaniards, came to hate Spanish methods of defending religion, especially after the Spaniards had massacred a band of French settlers in America. [Illustration: EMPEROR CHARLES V] THE "REFORMERS." Many men became discontented at the way the Church was managed. At first all were agreed that the evils of which they complained could be removed if priests, bishops, and pope worked together to that end. After a while some teachers in different countries not only complained of evils, but refused to believe as the Church had taught and as most people still believed. They did not mean to divide the Christian Church into several churches, but they thought they understood the words of the Bible better than the teachers of the Church.