Julius Caesar (102-44 BCE) was a military and political leader of ancient Rome, in what is now called Italy. The Roman Empire was the largest empire the world had known, and it expanded by conquests based on superior Roman military technology, engineering and organisation. Caesar was one of history's greatest generals, a great orator, and published as PR the accounts he wrote of his own successful military campaigns and conquest in Gaul, which is now France. He stated simply, in Latin, "Veni, vidi, vici" or "I came, I saw, I conquered." By political intrigue, charisma, bribery, military force, and civil war Caesar then transformed the Roman Republic into an empire with himself as dictator.

Caesar was tall, dark-eyed, well-dressed, bald, and physically very fit. He came from a well-connected patrician background, and advanced his early career and personal wealth in the usual Roman way by military and political service in provinces of the empire such as Hispania, now called Spain. At that time Rome was governed by a Senate and two annually elected Consuls who made executive decisions. In 60 BCE Caesar returned to Rome dissatified with the system of government. The hugely popular general Pompey, who had conquered Mithridates, Mediterranean pirates and Jerusalem, formed an alliance with Caesar and Crassus, the richest man in Rome, to govern as a triumvirate, or group of three. This ended constitutional government.

Caesar then served for nine years in Gaul, from 58 to 50 BCE, and subdued the opposing tribes and brought the Roman empire as far as the English Channel. He led the first Roman invasion of the island of Britain in 55 BC, losing some ships because they had no experience of the tide outside the Mediterranean sea. After a second invasion in 54 BCE the colonisation of Britain and Gaul followed, but the German tribes were still too fierce for the Romans to beat.

While Caesar was away from Rome relations with Pompey worsened and the triumvirate collapsed, and the Roman Senate told Caesar he must not lead his armies across the Rubicon river into Italy from the north. Caesar ignored them, crossed the Rubicon and started a civil war from which he emerged as ruler of the Italian peninsula and, in title, the Roman empire, though he had further battles ahead to take full control. Consequently the phrase "to cross the Rubicon" still means to make an important decision from which there is no turning back. Pompey fled to Egypt and was murdered there, and Caesar later conquered Egypt and put the highly intelligent polyglot Cleopatra in place as Queen of Egypt, and may have had a child with her.

After this coup de etat, Caesar initiated wide reforms of Roman society and the state, and the unreliable Roman calendar. He was declared dictator for life, and further centralised the state bureaucracy. A conspiracy of senators, led by Caesar's former friend Marcus Junius Brutus, stabbed the dictator to death on the Ides of March, or 15 March, in 44 BC. They hoped to restore the old Republic and the freedoms they valued which Caesar had abolished.

More civil war followed, and then power was given to Julius Caesar's appoiinted heir Octavian, also called Augustus Caesar or the Emperor Augustus, who was later proclaimed a god. As Rome's first emperor, Augustus defeated all his Roman enemies and brought expansion and peace. Roman urban planning, road construction, vineyards, Roman law, and the Latin language spread with the Empire, leaving European aqueducts, vineyards and road routes used to this day, as well as forming, from classical Latin, the modern Romance languages such as French, Italian, Spanish, and Portuguese.

The word "Caesar" became a title and respectful form for addressing Roman emperors. The titles Czar, or Tsar, and Kaiser are variations on the word "Caesar" and were later used to describe absolute rulers in Russia and Germany respectively, and in the English language a "caesar" can be a pejorative term for a despot or dictator.

Wrote a play about the conspiracy which murdered Caesar.  When Caesar is stabbed he turns to his friend Brutus  and says "Et tu, Brute?" meaning "And you, O Brutus?" and then Brutus too stabs him.
The murder took place on the fifteenth of March, also called the Ides of March, and Caesar had been warned to "Beware the Ides of March". The play also features a famous speech by Marc Antony, who says "Friends, Romans, Countrymen, lend me your ears...I come to bury Caesar, not to praise him" and then proceeds to praise Caesar and his memory and stir up the crowd.