The pope called on the king of Spain to help in this quarrel with Luther. The reason he called on him was this: The king of Spain was Charles V, the grandson of the Ferdinand and Isabella who had helped Columbus. He was not only a good Catholic but the most powerful ruler in Europe. The Spanish explorers had discovered different parts of America, and so Charles was owner of a large part of the New World. But he was emperor not only of these Spanish settlements in America but of Austria and of Germany as well. So it was quite natural that the pope should go to Charles for help. Charles commanded Luther to come to a city named Worms to be tried. He promised Luther that no harm would be done him, and so Luther went. When Luther arrived at Worms, Charles ordered him to take back all he had said. Luther refused to do so. Some of Charles’s nobles said Luther should be burned at the stake. But Charles, as he had promised, let him go and did not punish him for his belief. Luther’s friends were afraid, though, that other Catholics might do him harm. They knew Luther would take no care of himself, and so they themselves took him prisoner and kept him shut up for over a year, so that no one could harm him. While Luther was in prison he translated the Bible into German; it was the first time that the Bible had been written in that language. The people who protested against what the pope did were called Protest-ants, and those Christians who are not Roman Catholics are still called Protestants to-day. The time when these changes were made in the Catholic form of worship was called the Re-form-ation, as the old religion was _re-formed_. Now, you may be a Catholic and your best friend may not be a Catholic, but that makes no difference in your friendship. But at that time those who were Catholics were deadly enemies of those who were not. Each side was sure it alone was right and the other side was wrong. Each side fought for the things it thought were right, fought the other side as furiously and madly and bitterly as if the other side were scoundrels and devils. Friends and relatives murdered each other because they thought differently about religion, and yet all were supposed to be Christians. Charles was greatly worried and troubled by the religious quarrels and other difficulties in his vast empire. He became sick and tired of being emperor and of having to settle all the many problems he had to solve. He wanted to be free to do other things that he was more interested in. Being king did not mean being able to do whatever you wanted, as some people think. So Charles did what few rulers have ever done voluntarily: he resigned--“abdicated,” as it is called--and gave up his throne to his son, who was named Philip II. Then Charles, glad to be rid of all the cares of state, went to live in a monastery. There he spent his time doing what he liked--what do you suppose?--making mechanical toys and watches--until he died!