Gaius Julius Caesar (100 - 44 BCE), known as Julius Caesar or just Caesar, was a military and political leader in ancient Rome that eventually declared himself dictator for life (dictator perpetus). He spent a lot of time traveling around in military campaigns.

Caesar is one of the best-known and most important figures in world history, and especially in ancient history. In Rome, he was famous for conquering Gaul (modern-day France), which extended the Roman Empire to the Atlantic Ocean, and leading the first Roman invasion of Britain in 55 BCE.

Caesar was well-loved by the common people as a military and political leader in the Roman Republic. After he became famous as a general, Caesar assumed political power in a triumvirate with Marcus Licinius Crassus and Gnaeus Pompeius Magnus. Being of the populares (populist) political tradition, Caesar deemphasized the role of the Senate in favor of popular assemblies of common citizens. This led to various troubles with the Senate.

When Caesar's triumvirate collapsed, it caused a political crisis. Caesar restored order, and established his own dominance, by marching on Rome with his legions. After winning several engagements in a Roman civil war, Caesar established himself as dictator-for-life, much to the distaste of the Senate.

As Caesar acquired more popularity and power, some senators began to plot his assassination. After much thought over potential strategies, including the possibility of killing Caesar while on his favorite walking path, the senators decided to stab him right in the middle of the Senate chamber during a meeting. After Caesar was assassinated, the senators spilled out into the streets in joy. Caesar's assassination took place on what was called the Ides of March, the 15th day of the month.

The Roman people were angry that a small group of aristocrats had murdered their hero, and popular opinion turned against the Senate. Caesar's son became the focus on popular support in the ensuing civil war. After the conclusion of the war, Caesar's son took power as dictator, ending the centuries-long Roman Republic and replacing it with the monarchic Roman Empire.

Two years after his death, Caesar was deified in a ceremony, and formally added to the pantheon of Roman gods.