World History: 8. The Roman and Byzantine Empires, Lessons 5–7

When merchants realized that coins had less precious metal than before, they raised prices. This caused inflation, or a general rise in the cost of goods.

Despite good roads, communication and travel were much slower than they are today.

Romans called the Germans barbarians. This is the word Greeks and Romans used for all people who did not share their cultures.

Rome declined after Constantine's death. Its enemies took advantage of its weakness and caused it to collapse.

They hired mercenaries, or soldiers who fight for pay rather than for their country.

Theodosius became a strong supporter of Christian orthodoxy, meaning traditional or established religious beliefs.

A strait is a narrow body of water that cuts through land, connecting two larger bodies of water.

Two rings of thick walls and a moat, or a trench filled with water, protected the city on land.

Justinian was his successor.

However, the Byzantine emperors kept control of the core of their empire, modern-day Greece and western Turkey.

A missionary is someone who tries to convert others to a particular religion.

They met in the city of Nicea and adopted a statement of beliefs, or a creed, called the Nicene Creed.

An icon is a holy image, usually a portrait of Jesus or a saint.

People who opposed icons were called iconoclasts, meaning "image-breakers."

Over time, however, the bishop of Rome claimed authority over Christians everywhere. He began to be called pope, which means father, or head, of the Church.

He had them produce a unified code, or systematic body of law.

For example, the code discriminated against Jews and other non-Christians.