How long did the Roman Empire last?
The Roman Empire lasted from 27 BC to 1453.
The Roman empire was founded in 27 BC after the assassination of its first ruler, Julius Caesar. It grew and thrived until it started to decline after the rise of Christianity at around 300 AD, which put an end to many pagan traditions. In 476 the last Western Roman emperor was deposed by Germanic tribes led by Odoacer who installed himself as king of Italy. This began a long vice where Rome was repeatedly sacked by various northern barbarians including Goths and Vikings while also grappling with outbreaks of bubonic plague, malaria, measles, influenza and smallpox amongst other horrendous diseases that targeted south Europeans due to their centuries-long absence from exposure combined with low genetic immunity.
After the fall of the Western Roman empire, The Eastern Empire remained intact for 1000 more years until Constantinople was conquered by the Ottoman Turks in 1453 who put an end to the Byzantine and ancient Greek empires simultaneously. A few small Greek states still exist but they are not as large or powerful as their predecessors were during Ancient Greece and Rome.