49 BC

By place and Date

Roman Republic

• Consuls: Lucius Cornelius Lentulus Crus, Gaius Claudius Marcellus Maior.
• Caesar's Civil War commences:
• * January 1 - The Roman Senate receives a proposal from Julius Caesar that he and Pompey should lay down their commands simultaneously. The Senate responds that Caesar must immediately surrender his command.
• * January 10 - Caesar leads his army across the Rubicon, which separates his jurisdiction in Cisalpine Gaul from that of the Senate in Rome, and thus initiates a civil war. In response, the Senate invokes the senatus consultum ultimum.
• * February - Pompey's flight to Epirus with most of the Senate.
• * March 9 - Caesar advances against Pompeian forces in Spain.
• * April 19 - Siege of Massilia: Caesar commences a siege at Massilia against the Pompeian Lucius Domitius Ahenobarbus. He leaves the newly raised legions XVII, XVIII and XIX to conduct the siege. Decimus Brutus – victor over the Veneti – is in charge of the fleet to blockade the harbor.
• * June - Caesar arrives in Spain; seizes the Pyrenees passes against the Pompeians L. Afranius and Marcus Petreius.
• * June 7 - Cicero slips out of Italy and goes to Thessaloniki.
• * July 30 - Caesar surrounds Afranius and Petreius's army in Ilerda.
• * August 2 - Pompeians in Ilerda surrender to Caesar and are granted pardon.
• * August 24 - Caesar's general Gaius Scribonius Curio is defeated in North Africa by the Pompeians under Attius Varus and King Juba I of Numidia in the Battle of the Bagradas, after which he commits suicide.
• * September - Brutus defeats the combined Pompeian-Massilian naval forces of the siege of Massilia, while the Caesarian fleet in the Adriatic Sea is defeated near Curicta.
• * September 6 - Massilia surrenders to Caesar, as he is coming back from Spain.
• * October - Caesar is appointed Dictator in Rome.