Rome, Ancient, city-state in central Italy that grew into a vast empire. At its height, in A.D. 117, it comprised most of the known Western world. The ancient Romans made great advances in the fields of law, civil engineering, standardization in coinage and measurement, philosophy, architecture, and literature. The region was controlled by the Etruscans until Romans established an independent republic in 500 B.C. Throughout the period of the republic (500–31 B.C.), warfare was almost continuous. Under a government controlled by consuls and the senate, Rome overran central and southern Italy and defeated Carthage. Expansion continued to Greece, Asia Minor, Syria, Palestine, and Egypt, Gaul, and England. From about 100 B.C., Rome began to move steadily toward disaster. Civil wars arose from conflicts between senatorial factions, and between rich and poor. The army leaders Pompey and Julius Caesar arose to form the first Triumverate with Crassus. After the assassination of Caesar, Caesar's nephew Octavian defeated Antony and became the first emperor of Rome, renaming himself Augustus. For more than 200 years (27 B.C.–A.D. 180) the empire flourished. The establishment of trade routes throughout the empire lead to the spread of new ideas, particularly Christianity. From about A.D. 200 the period was characterized by internal strife and barbarian raids. Under Constantine I (emperor 306–337) the capital was moved to Byzantium (renamed Constantinople), and Christianity was officially recognized. At the beginning of the fifth century, the empire was divided into East and West, and a period of barbarian invasion and vandalism followed.