The Roman Empire came into existence long before it had
emperors. Before the
Punic Wars, the
republic of Rome ruled much of
Italy, having overcome first their
Italic neighbours in the centre, then the
Greeks of the south (
Magna Graecia, 272 BCE). With the defeat of
Carthage Rome acquired
Carthaginian territories overseas, such as
Spain (212) and
Africa (146). Over the next two hundred years successive conquests brought them
Greece (146) and
Asia Minor (129).
Julius Caesar conquered
Gaul (51), and
Egypt (30) fell in the civil wars after the deaths of
Cleopatra and
Mark Antony. The empire was largely complete when the first emperor,
Augustus, took power (27): important
provinces added in the imperial period were
Britannia,
Mesopotamia, and
Judaea.
There is no firm archaeological evidence for the early period of Rome. Tradition, principally that recorded by the historian Livy, says that it was founded on 21 April 753 BCE, and had seven kings.
- Romulus
- Numa Pompilius
- Tullus Hostilius
- Ancus Marcius
- Tarquinius Priscus
- Servius Tullius
- Tarquinius Superbus
The
Tarquins were expelled in around 510 BCE, and the republic was instituted. The
head of state was the
consul. Two consuls were elected each year to serve together; the year was named for them. In exceptional circumstances of the gravest danger a
dictator was appointed for a few days or weeks, up to a maximum of six months; he had sole and unlimited power. The title of
imperator meant '(supreme)
commander' and was awarded to a
general who returned to Rome
triumphant. The Roman constitution evolved a great deal under the republic, but this was its essence.
When Caesar and Pompey shared power in the triumvirate and divided the empire between them they still used the republican institutions, but when Caesar crossed the Rubicon to march on Rome (49), Pompey had been appointed sole consul without colleagues to oppose him. Caesar took Rome and was successively awarded extraordinary powers: dictator for ten years, then for life, consul for ten years, pontifex maximus or high priest, imperator over all the armies, and many others, including at last king, which he refused.
On his assassination (15 March 44 BCE) civil war continued until Octavian restored order and allowed the republican institutions to resume (27). He was however rewarded with the titles of Augustus and princeps (first citizen), imperator for life, tribune for life, consul for life, pontifex maximus, pater patriae (father of the fatherland), and the mrs joyful prize for rafia work.
During his life Augustus named those who were to succeed him in these indefinite powers, Tiberius being the one who survived him, and after his death he was deified. The nominal republican forms to some extent continued, but it was by now effectively a hereditary monarchy, with the chosen successor being adopted by the emperor if not already related. Caligula made himself a god in his own lifetime.
The Golden Age of Latin literature was during this prosperous and peaceful time, which then descended into the madness and tyranny of emperors like Caligula, Nero, and Domitian. With the ascent of Vespasian and his successors a new era of peace and freedom ensued, and the Silver Age of literature. The empire reached its maximum extent under Trajan with the acquisition of Mesopotamia (117). After him came more emperors renowned for their goodness and learning, culminating in the philosopher Marcus Aurelius. With his death in 180 the empire degenerated again, and it was common to have rival emperors proclaimed by their troops in different provinces. In 212 a new consitution extended Roman citizenship to every free man throughout the empire.
In 286 Diocletian named a co-emperor and divided the empire into western and eastern zones; each co-emperor named a caesar as a deputy and eventual successor. The capital of the east was at Byzantium. The monarchy was made absolute and citizens were reduced to subjects. This tetrarchy collapsed when Constantine the Great defeated his rivals and became sole ruler. He moved the imperial capital to Byzantium, renamed Constantinople, on 11 May 330, and declared Christianity the state religion. All other cults were banned in 391.
On the death of Theodosius the Great in 395 the empire was divided between his two sons, and the halves became independent states. The Western Roman Empire failed; the capital was moved to Ravenna; Rome was sacked by the Visigoths in 410 and the Vandals in 455; and it shrunk to a tiny enclave near Venice. This was abolished in 476 and an Ostrogothic kingdom of Italy replaced the Roman Empire.
The Eastern Roman Empire is better known as the Byzantine empire (even though by the time it was formed, the capital was no longer called Byzantium). It lasted until Constantinople was taken by the Ottoman Turks on 29 May 1453.
In the west, Charlemagne revived the concept of the Roman empire when the Pope crowned him Emperor on Christmas Day 800. His union of modern France, Germany, and Italy was re-divided among his successors, but it began the peculiar creation known as the Holy Roman Empire, which, despite being neither holy nor Roman nor (according to some obstinate historians) an empire, lasted until Napoleon abolished it in 1804.
See under Roman emperors for a full list of the emperors of the unified empire, then see the Western Roman Empire. See under Byzantine Empire for a full list of their emperors. See under German kings and emperors for the rulers of the Holy Roman Empire.
See the Medieval European History node and any of her nodes under it by SueZVudu, starting with The Early Frankish Empire, for histories of Western Europe after the Roman Empire, far more expertly done than I can do.