Roman Empire Mediterranean empire formed (c.27 bc) by Augustus after the assassination (c.44 bc) of Julius Caesar. Its power centre was ancient Rome. The Romans adopted the culture of ancient Greece, but their Empire was based on military power and Roman law. In terms of technology and (arguably) culture, Roman civilization was not surpassed in Europe until the Renaissance. By the death of Augustus (ad 14), the Empire included most of Asia Minor, Syria, Egypt, and the whole North African coast. In the 1st and 2nd centuries, Britain was conquered; in the e, Roman rule extended to the Caspian Sea and the Persian Gulf, and further territory, including Dacia (Transylvania), was added in se Europe. The Empire was at its greatest extent at the death of Trajan (ad 117), when it included all the lands around the Mediterranean and extended to n Britain, the Black Sea, and Mesopotamia. Hadrian (r.117–138) called a halt to further expansion. Rome reached the height of its power during the first 150 years of imperial rule, becoming a city of grand, monumental buildings with c.1 million inhabitants. In the 3rd century, pressure from Germanic tribes and the Persians, plus economic difficulties, contributed to the breakdown of government. Armies in the provinces broke away from Rome. Diocletian restored order, and from his time the Empire tended to be split into e and w divisions. In 330, Constantine founded an e capital at Constantinople. Rome was increasingly challenged by different peoples, such as the Goths who sacked the city in 410. By 500, the Roman Empire in the west had ceased to exist. The Eastern or Byzantine Empire survived until 1453.

Ro·man Em·pire the empire established by Augustus in 27 bc and divided by Theodosius in ad 395 into the Western or Latin and Eastern or Greek Empire.

Roman Empire: see Rome; Byzantine Empire; Holy Roman Empire.