- "Pompey said he would have my head for going against the Senate but when I lead my army across the Rubicon, Rome will welcome me as a god."
- —Julius Caesar[src]
Gaius Julius Caesar (died March 15, 44 BC), simply known as Julius Caesar, was the last ruler of the Roman Republic. He wound up as an anachronism in Aruba, 2017, before being returned to his time in Rome by the Legends.
When Julius Caesar was young, he was kidnapped by pirates in exchange for an expensive ransom amounting to 50 talents of silver. His parents paid the ransom, but not before Caesar declared to his captors that if he was to be freed instead of being killed, they would see him once more to not only take back his silver, but to also crucify them one by one. Julius was eventually released and once capable enough, he delivered on his promise to the pirates.
At some point in time, Vandal Savage served as one of the assistants of Caesar, who in turn most likely caused the Gallic Wars. Caesar's conquest of Gaul had cost him eight years and the countless deaths of his centurions.
Before Caesar's famous march on the Rubicon, Pompey declared that he would take Caesar's head off for going against the Senate of the Roman Republic. In 49 BC, he and his army set up camp in Cisalpine Gaul to prepare for the march. On the night before their departure, Julius Caesar wore his full armor and rode on his steed, when he suddenly found himself on a beach in 2017. This was a result of the Legends' accidental creation of a time storm, resulting into the displacement of Caesar in Aruba, 2017 as an anachronism.
Speculating that he ended up on the beach due to the mischief of the goddess Até, Caesar approached Mick Rory and declared his eventual conquest of the known world. Annoyed, Mick abducted Caesar, tied him up on a chair in his casita, and called Sara Lance to fill her in on his situation. After Mick exclaimed in dismay on his Caesar salad (who referred to another Caesar), Julius Caesar told his story of when he was abducted by pirates, and later, crucifying them for sparing his life. He used this story to threaten Mick to just get his life over with, before he offered his satchel of gold to Rory, but at the cost of the captor's life. Mick grabbed the satchel from his hip, when the coins fell on the ground. Caesar used the opportunity to break free and attack Mick. He bested his captor and escaped from the casita.
Later that afternoon, Caesar was found by the Legends attempting to rally a group of Roman soldiers, unaware they were simply a fraternity dressed in togas. He was about to lead his "legion" into battle when they were distracted by their Upswipz app on their phones. Sara then ordered Caesar to come with the Legends. Refusing to surrender to a woman, Caesar briefly dueled and was incapacitated by Sara. The Legends imprisoned him on the Waverider, with Mick tempted to break Caesar's nose just as he broke his.
When Sara entered Caesar's holding cell, the general asked if the captain would either gloat or grant him the mercy of taking his own life, as being outmatched by a woman nagged him. However, Sara was otherwise interested in neither choice. Feeling that Sara doubted her present course of action and/or she left her decision up to the Three Fates, Caesar tried to get a rise out of her by enumerating his accomplishments and aspirations and expressed that Sara would make a fine queen, who begged to differ.
When Jefferson Jackson deemed the Waverider fully operational, the Legends flew to Cisalpine Gaul, 49 BC, where Sara and Nate Heywood placed Caesar on the day right after he was displaced. After using the memory flasher on Caesar, Nate took a quick selfie with him. Unbeknownst to the captain and the historian, the general stole Nate's book titled Rise of Rome, which contained information on the ancient Roman empire, and the memory flasher did nothing to Caesar. He learned about his assassination in the chapter titled "The Ides of March" and planned to kill two of its biggest conspirators, Cassius and Brutus, before they could assassinate him.
Aberrant timeline: Thanks to the knowledge from the book Rise of Rome, Caesar was able to empower ancient Rome to such extent that the Roman Empire never fell, and went to conquer the known and unknown world, with his conquest of Magna Hesperia, a Roman-colonized territory of North America that was originally supposed to become the United States, as one of his greatest achievements.
Current timeline: Prior to his march on the Rubicon, Caesar anticipated interference and, thus, set a trap by emptying his camp, leaving Rise of Rome on a table in his tent. When two Time Bureau agents led by Ava Sharpe arrived to retrieve the book, Caesar ambushed the trio outside the tent, managing to capture Sharpe while her compatriots fled through a portal back to the Waverider. Deciding to spare Sharpe, Caesar held her captive as he began his march towards Rome, only to be attacked by the Legends. At the end of the battle, Caesar was knocked out by Rory as payback for breaking his nose. Afterwards, the Time Bureau erased the memories of Julius and his army, averting the alternate timeline.
The Rubicon and the civil war
After the demon Mallus escaped from his his prison, he imbued his powers to Caesar, Freydis, and Blackbeard, making them his worshippers. Mallus sent them to the town of Salvation, North Dakota, in1874, where the three confronted the Legends and town sheriff Jonah Hex. Under Mallus' influence, they gave the Legends the demon's ultimatum for the surrender of the six Totems of Zambesi in exchange for sparing their and the townspeople's lives, to which the totem-bearers declined.
The next day, the three arrived with their armies of Romans, vikings, and pirates to find Sara holding all six totems, before she turned tail and rode on a horse. Caesar declared war upon the town and went into the nearby tavern with his men, where he battled Mick once more and got his nose broken as retribution, but was replenished by Mallus's power a few minutes later. After Mallus finally arrived near the town, Caesar and his allies all stopped fighting and bowed in reverence to their new god. Their power from Mallus disappeared after the six totem-bearers defeated the time demon. Caesar, along with Freydis and Blackbeard, was brought to the Time Bureau by Director Ava Sharpe and Jax, had his memory of the incident wiped, and returned to his time period.
At some point, Julius Caesar became the dictator of the Roman Republic.
On March 15, the day known as the Ides of March, 44 BC, Caesar was traveling in the capital when Brutus, Cassius, and several other senators mobbed Caesar and killed him at the Theatre of Pompey, ending his reign.
The Ides of March became notoriously well-known for his death in 44 BC. Caesar's death precipitated the end of the Roman Republic and the rise of the Roman Empire. His autobiography was admired by many for his military and political prowess. Caesar became known in pop culture, such as within the expression "Great Caesar's ghost!"
Julius Caesar was a man of great pride and megalomaniac ambitions, seeing fit to conquer the whole known world regardless of the location or the time period he was in. His pride was hurt greatly after being defeated by a woman, though seeing as she later sought his advice, Julius' opinion changed on trying to make Sara Lance, the "Amazon warrior" that she is, into his empress to conquer the world with. Julius was unrelenting in his ambitions and focus, refusing to give up, and giving the advice to do the same to Sara. He considered himself fair and truthful, warning his enemies of the impending revenge should they let him ago after a wrongdoing he suffered at their hands.
- Peak of human physical condition: As en esteemed war general, Caesar was in remarkable physical form with excellent conditioning.
- High-level intellect/Master tactician/Leader: Caesar was a man of impressive intellect, able to become a Consul of Rome, lead its armies, and later take over as a dictator. Even stuck in a foreign place at a different time, he was barely distraught and instead ready to conquer a new world. Julius conquered many territories, most notably Gaul, and took on Rome itself despite the orders of the Senate. Using his experience with taking risks, Caesar was able to advise Sara Lance on how to deal with the Time Bureau. Aside from his knowledge of strategy, Caesar was also a direct tactician, baiting the agents of Time Bureau into a trap and capturing Ava Sharpe.
- Expert hand-to-hand combatant: Julius trained in unarmed combat to such a level that he was able to escape his bounds and incapacitate Mick Rory, who is a very capable fighter in his own right, even when Mick had dominated the Roman leader during most of the fight. However, Caesar was easily beaten by Sara and later Mick with a single punch during their second clash. In his third confrontation with Mick, Caesar was easily beaten by the pyromaniac.
- Indomitable will: Julius never gave up under any circumstances and always sought to take revenge on his enemies. Stuck between a seemingly impossible choice he pressed one, ready to risk everything.
- Temporal linguistic dysplasia: Due to the nature of anachronisms caused by time travel, Caesar was able to flawlessly speak and understand modern English while in Aruba, 2017, a language that did not exist in the times of Ancient Rome. Apparently, he maintained this ability after he was returned to his time, as he succeeded to read the book Rise of Rome. 
- Knowledge of future history: Using the book Rise of Rome, Caesar was able to correct his mistakes by seeing how history would unravel.
- Roman military armor: Caesar wore this whenever he went to war.
- Sword: Caesar mainly used a sword as his weapon in battle.