Augustus(63 B.C.-14 A.D.), the first Roman emperor. He was originally named Gaius Octavius and was later called Gaius Julius Caesar Octavianus (or, in English, Octavian). The title of Augustus (majestic) was awarded him in 27 B.C. by the Roman Senate in gratitude for his having brought almost 20 years of civil warfare to an end. Although he was never actually proclaimed emperor, he is considered the first Roman emperor because he held supreme authority for the rest of his life and passed it on to his heirs. Augustus' firm and wise rule inaugurated two centuries of growth, prosperity, and peace in the empire.

Octavian was a grandson of the sister of Julius Caesar and was named in Caesar's will as his adopted son and heir. Octavian was only 18 at the time of Caesar's death (44 B.C.). Upon arriving in Rome to assume the legacy, he found that Mark Antony had appropriated Caesar's fortune. By borrowing money, Octavian distributed Caesar's bequests to his troops and gained the support of several legions. He then joined forces with the Senate in driving Antony from Rome. However, he soon realized that the Senate did not intend to punish the murderers of Caesar. Since Antony shared his determination to avenge Caesar's death, Octavian formed a triumvirate (ruling trio) with Antony and his ally Lepidus in 43 B.C.

The triumvirate, proclaimed the official government, put to death more than 2,000 persons considered enemies and defeated Caesar's murderers in battle at Philippi (42 B.C.). Conflict developed between Octavian and Antony, but peace was restored in 40 B.C. with the marriage of Octavian's sister, Octavia, to Antony. Octavian had the west to rule; Antony, the east; Lepidus, Africa. Lepidus, however, tried to take territory from Octavian and was stripped of power. Antony, having deserted Octavia for Cleopatra of Egypt, was thought to be planning his own empire centered in Egypt. At the sea battle of Actium (31 B.C.), Octavian defeated the forces of Antony and Cleopatra; a year later he occupied Egypt.

Octavian returned to Rome in 29 B.C. as master of the Roman empire. The government that he established was nominally a restoration of the republic, but the Senate repeatedly gave him special powers, often for life. He was permanent imperator (commander in chief) and was acknowledged as princeps (head of state).

The ruthlessness of Octavian's earlier years was gone, and his rule was devoted to creating stable conditions throughout the empire. He made many administrative reforms and attempted to restore public and private morality. His reign is known as the Augustan Age—the golden age of Roman architecture and literature, famous for the writings of Virgil, Horace, Ovid, and Livy.

Augustus was succeeded by his stepson Tiberius.