In most English-speaking countries, a person who is accused of a crime has the right to a trial by jury. In a trial by jury, the guilt or innocence of the accused person is decided by a group of 12 people, called jurors, who must listen to the evidence about the case. The idea of trial by jury is over 800 years old, but there was a time when criminal cases were decided in other ways. Today, many of these methods seem ridiculous and cruel. Many accused people were forced to undergo a trial by ordeal. There were several different kinds of this trial. For example, in the ordeal by fire, an accused man was forced to carry a red-hot piece of iron in his hand. People believed that if the men were innocent then the gods would protect him, and his hand would not be burned or blistered by the iron. Another form of the trial by ordeal was the ordeal by combat. If one person accused another of a crime, they would be forced to fight each other with some weapon. People believed that the gods would help the man who was right and allow him to win the fight. Yet another kind of ordeal was the ordeal by water. If a woman was accused of a crime, such as witchcraft, she might be thrown into a river with rocks attached to her. People believed that the gods would help an innocent woman and allow her to float on the water. Gradually, people realized that the trial by ordeal was a completely worthless way to judge a person's innocence or guilt. They wanted a less barbaric way to decide criminal cases. During the twelfth century, a new method was introduced by one of the kings of England, Henry the Second. Henry said that criminal cases should be decided by the opinions of twelve honest men who knew about the crime, the victim, and the accused person. This was the beginning of trial by jury in English-speaking countries, and the method soon became very popular. People trusted this new method much more than they trusted the old methods. Later, the system of trial by jury changed somewhat. Instead of having a jury of twelve men and women who knew about the crime, juries were chosen so that the twelve people did not know anything about the crime. This change ensures that the jurors do not have any bias or prejudice about the case. When jurors do not know any of the people involved in the case, their decisions are more likely to be fair and accurate. Today, citizens in many countries are called occasionally for jury duty. This can be inconvenient for people who are busy with their work and family life. However, many men and women are willing to serve on juries because of a feeling of responsibility to society. The use of juries in criminal cases helps to ensure that justice is done.