Short answers, pulled from the story.
Julius Caesar was a Roman general, statesman, and author who served as dictator of the Roman Republic almost continuously from 49 BC until his assassination in 44 BC. He led the Roman armies through the Gallic Wars, defeated his rival Pompey in a civil war, and proclaimed himself dictator for life in 44 BC.
Julius Caesar was born on the 12th or the 13th of July 100 BC and died on the 15th of March 44 BC, the Ides of March. He was assassinated in the Curia of Pompey by a group of senators led by Brutus and Cassius.
Julius Caesar crossed the Rubicon around the 10th or the 11th of January 49 BC with a single legion, the Legio XIII Gemina, after the Senate declared him an enemy and drove out his supportive tribunes. The crossing began his civil war against Pompey and the Senate. Plutarch and Suetonius say he quoted Menander in Greek, "let the die be cast".
Julius Caesar was assassinated because senators feared his power, his domination of the state, and the possibility that he might make himself king. Shortly before the 15th of February 44 BC he had assumed the title dictator for life, ending hopes that his power would be temporary. Some sixty conspirators, led by Brutus and Cassius, stabbed him at least twenty-three times on the 15th of March 44 BC.
Caesar's cognomen became a synonym for emperor and was used throughout the Roman Empire. It passed into German as Kaiser and, through Old Church Slavic, into the Slavic Tsar or Czar. For roughly two thousand years, at least one head of state has borne his name, the last Tsar in nominal power being Simeon II of Bulgaria.
Julius Caesar replaced the republican lunisolar calendar with the solar Julian calendar, increased the number of senators from 600 to 900, and founded colonies on the sites of Carthage and Corinth. He also reduced the grain dole from 320,000 to around 150,000 recipients and extended citizenship to communities in Cisalpine Gaul and to Cádiz.
Only Julius Caesar's war commentaries survive, including The Gallic Wars, seven books each covering one year of his campaigns in Gaul and southern Britain in the 50s BC, with an eighth book written by Aulus Hirtius. He also wrote The Civil War. His lost works include a funeral oration for his aunt Julia and the "Anticato", an attack on Cato written in response to Cicero's eulogy.