Rome, the chief city of Italy, created the largest empire the  world has ever saw. The population of the Roman Empire numbered about 100,000,000 people at itís height. The entire civilized world became part of the Roman Empire. In Rome itself there was only 1,000,000 people. Everyone else came from Britain to Persia.     Great modern nations such as England, France, Spain, Italy, and many countries of Asia grew from the Roman Empire. All these areas were  protected by the same armies and lived under the same laws. They also paid their taxes directly  to the Roman treasury.
 The government in Rome decided how to distribute theses taxes. The entire government was located in Rome. Most of the government officials lived in Rome, as well as the public buildings. These officials sent engineers throughout the  Empire to build roads and bridges, which spead up the movement of soldiers, merchants, and commerce.
 Since it was so difficult to protect such large  areas and roads, revolts and border wars flared up often. The Roman army almost always managed to retain control. These Roman soldiers were citizens who were paid by the state, but had to buy their own equipment.  This included a bronze breastplate, a leather shield, an iron sword, and spears or javelins. Toses who could afford horses joined the cavalry.
  For hundreds of years, this great army  fought Barbarian invasions from the north and south and Persian armies from the cost. When the fighting came to an end it was the emperor Diocletian  who finally succeeded in establishing peace and order. Diocletian ruled by himself, without help and advice from a senate or anyone else.
 After Diocletion, Romeís next emperor was Constantine the Great.  Constantine was perhaps the most important ruler in history. This emperor became Romeís Christian emperor and introduced Christianity throughout the Roman empire.  When he conquered his enemies, Constantine converted them to Christianity. Most important, the Christians, instead of being persecuted as they had been for  so long, saw their religion become the state religion.
 Constantine founded a new capital of  the Roman Empire. He named this capitol after himself, and called it Constantinople.  He  moved  the government out of  Rome because he thought as a dictator,  he should have his own imperial  capital.