For thousands of years, leaders have set out to take control of other societies. Some have done it to win more power. Others have wanted to become rich. And others tried to make their empires stronger.

Over time, many empires have risen and fallen. Conquerers have used large armies to take power. What drove these rulers to conquer new lands?

There were several reasons. One was the chance to grab another land's riches. That was the reason Rome's Julius Caesar conquered Gaul in 58 B.C.E. Gaul covered parts of modern-day France, Switzerland, Belgium, Luxembourg, Germany, and northern Italy.

Another reason was the desire to trade. The Mongols were a people in Asia. They wanted to take control of the Silk Road. The Silk Road was a set of trade routes. It stretched across Asia and into Europe.

Alexander of Macedonia (also known as Alexander the Great), Julius Caesar, and William the Conqueror are three legendary conquerors. All three created and then grew their empires. They did this to win power and riches. Having a larger empire was not only about having more land. It also meant having more people to tax. More taxes helped the conquerors become rich.

Alexander

Alexander the Great became king of the Greeks in Macedonia at 20 years old. He was an ironfisted ruler. He crushed rebellions and killed his enemies. Alexander was also a master at making war. He led his armies with great military skill.

Julius Caesar

Julius Caesar first built his power in Rome. Then, he strengthened Rome's power through conquest. Rome grew far richer during his rule. Of course, much of those riches went to Caesar.

William

William first strengthened his power in Normandy, in France. Then, he conquered England. William completely changed English society. As king of England, he moved state power into the hands of his people, the French Normans. He did the same with the country's wealth.

Many of history's ancient conquerors believed they had a right to rule. Alexander thought he was the son of Zeus. Because of this, he felt that he deserved power. William was certain he was meant to rule England. Genghis Khan also believed he was meant to become a leader.

The desire for power is clearly very strong in history's leaders. Conquerors face overwhelming dangers for a chance to rule. Yet, they are willing to face these dangers. They believe the rewards are greater than the risks.