- "Caesar moves away from the Senate, placing his trust in foreign rulers, adopting the ego and pomp of his Egyptian whore. [...] [He] refuses to rise when he addresses us and scoffs at our concerns. He has created his own private senate, filled with deceivers, manipulators, people who have no business in Roman affairs."
- ―Marcus Junius Brutus.[src]
Gaius Julius Caesar (100 BCE – 44 BCE), known as Julius Caesar, was a prominent general of the Roman Army and a notable politician of the Roman Republic. He played a key role in transforming the troubled Republic into the seemingly unstoppable Roman Empire.
Around 59 BCE, Caesar founded the city of Florentia, later known as Florence. He rose to prominence for his success in the Gallic Wars, in which he defeated the chieftain Vercingetorix and allowed the Roman Republic to annex Gaul.
In 49 BCE, he and his forces entered Rome in the midst of civil war, and Caesar took power as the dictator of the Republic, while secretly being supported by the Templar Order. The year after, he met the Egyptian Queen Cleopatra and began an affair with her. Aided by the Templars, he installed her as the Pharaoh of Egypt. Caesar moved his attention away from the Roman Senate and scoffed at their concerns, instead placing his trust in foreign rulers and his own circle of senators. He also adopted the lavish and self-centered lifestyle of Cleopatra.
Led by Marcus Junius Brutus and Gaius Cassius Longinus, a group of forty senators calling themselves Liberatores, who were secretly members of the Assassin Brotherhood, began plotting against Caesar. Resolving to assassinate the dictator, the conspirators stabbed him twenty-three times on 15 March 44 BCE. Despite the death of Caesar, civil war continued for another thirteen years, as the armies of Brutus and Longinus clashed with those of Marcus Antonius and Octavian, Caesar's adopted son. Octavian eventually rose as the sole victor, naming himself Augustus and establishing the Roman Empire.
- There is a trophy for the PlayStation 3 in Assassin's Creed: Brotherhood named after Julius Caesar. It is earned by gaining all other trophies, fifty in total. Also, the Dagger of Brutus, which was used by Marcus Junius Brutus to kill Caesar, can be obtained.
- The popular Caesar cipher code format is widely attributed to have been designed by Caesar, hence its name. The code has often been used in the Assassin's Creed series, most commonly in secret messages left behind by Clay Kaczmarek.
- Historically, the person who started Caesar's assassination was Cassius, whom at first, Caesar managed to block his move and questioned his motive for trying to kill him. Cassius later called out his fellow senators, including Brutus for help in which, senators who opposed Caesar joined him in killing the dictator. Additionally, a story persists that Caesar's second wife tried to prevent him from going to a meeting when an oracle reputedly told her that he would die in the same day, which he rebuked.
- When Aya questioned Septimius that what importance does Julius Caesar hold for the Order of the Ancients, Septimius states that Julius Caesar is the Father of Understanding.
- Assassin's Creed: Project Legacy (mentioned only)
- Assassin's Creed: Brotherhood (mentioned only)
- Assassin's Creed: Origins (first appearance)