Roman Empire
  • Senatus Populusque Romanus  (Latin)
  • Imperium Romanum  (Latin)
  • Βασιλεία τῶν Ῥωμαίων (Ancient Greek)
    Basileía tôn Rhōmaíōn
27 BC–AD 395(unified)
AD 395–476/480(Western)
AD 395–1453(Eastern)
Flag of Roman Empire
Vexillum
with the imperialaquila
Imperial aquila of Roman Empire
Imperialaquila
The Roman Empire in AD 117 at its greatest extent, at the time of Trajan's death (with its vassals in pink)[3]
The Roman Empire in AD 117 at its greatest extent, at the time of Trajan's death (with its vassals in pink)
Capital
  • Rome
    (27 BC–AD 286)
  • Mediolanum
    (286–402, West)
  • Ravenna
    (402–476, West)
  • Nicomedia
    (286–330, East)
  • Constantinople
    (330–1453, East)
Common languages
  • Latin and Greek
  • Regional / local languages
Religion
  • Imperial cult-driven polytheism
    (Before AD 274)
  • Joined by the henotheistic solar cult of Sol Invictus
    (Before AD 380)
  • Nicene Christianity
    (officially from AD 380)
Demonym(s)Roman
GovernmentSemi-elective, functionally absolute monarchy
Emperor 
• 27 BC – AD 14
Augustus (first)
• 98–117
Trajan
• 270–275
Aurelian
• 284–305
Diocletian
• 306–337
Constantine I
• 379–395
Theodosius I
• 474–480
Julius Nepos
• 475–476
Romulus Augustus
• 527–565
Justinian I
• 610–641
Heraclius
• 780–797
Constantine VI
• 976–1025
Basil II
• 1143–1180
Manuel I
• 1449–1453
Constantine XI
Historical eraClassical era to Late Middle Ages
• War of Actium
32–30 BC
• Empire established
30–2 BC
• Octavian namedaugustus
16 January 27 BC
• Constantinople
becomes capital
11 May 330
• Final East-West divide
17 January 395
• Deposition of Romulus Augustus
4 September 476
• Murder of Julius Nepos
9 May 480
• Fourth Crusade
12 April 1204
• Reconquest of Constantinople
25 July 1261
• Fall of Constantinople
29 May 1453
• Fall of Trebizond
15 August 1461
Area
25 BC2,750,000 km2(1,060,000 sq mi)
AD 1175,000,000 km2(1,900,000 sq mi)
AD 3903,400,000 km2(1,300,000 sq mi)
Population
• 25 BC
56,800,000
Currencysestertius, aureus, solidus, nomisma
Preceded by
Succeeded by
Roman Republic
Western Roman Empire
Eastern Roman Empire