Gaius Julius Caesar (; 12 or 13 July 100 BC - 15 March 44 BC), known by his cognomen Julius Caesar, was a Roman politician and military general who played a critical role in the events that led to the demise of the Roman Republic and the rise of the Roman Empire. He is also known as a notable author of Latin prose. In 60 BC, Caesar, Crassus and Pompey formed a political alliance that dominated Roman politics for several years.

In 60 BC, Caesar sought election as consul for 59 BC, along with two other candidates. The election was sordid - even Cato, with his reputation for incorruptibility, is said to have resorted to bribery in favour of one of Caesar's opponents. Caesar won, along with conservative Marcus Bibulus.  Caesar was already in Crassus' political debt, but he also made overtures to Pompey. Pompey and Crassus had been at odds for a decade, so Caesar tried to reconcile them. The three of them had enough money and political influence to control public business. This informal alliance, known as the First Triumvirate ("rule of three men"), was cemented by the marriage of Pompey to Caesar's daughter Julia. Caesar also married again, this time Calpurnia, who was the daughter of another powerful senator.  Caesar proposed a law for redistributing public lands to the poor--by force of arms, if need be--a proposal supported by Pompey and by Crassus, making the triumvirate public. Pompey filled the city with soldiers, a move which intimidated the triumvirate's opponents. Bibulus attempted to declare the omens unfavourable and thus void the new law, but he was driven from the forum by Caesar's armed supporters. His bodyguards had their ceremonial axes broken, two high magistrates accompanying him were wounded, and he had a bucket of excrement thrown over him. In fear of his life, he retired to his house for the rest of the year, issuing occasional proclamations of bad omens. These attempts proved ineffective in obstructing Caesar's legislation. Roman satirists ever after referred to the year as "the consulship of Julius and Caesar."  When Caesar was first elected, the aristocracy tried to limit his future power by allotting the woods and pastures of Italy, rather than the governorship of a province, as his military command duty after his year in office was over. With the help of political allies, Caesar later overturned this, and was instead appointed to govern Cisalpine Gaul (northern Italy) and Illyricum (southeastern Europe), with Transalpine Gaul (southern France) later added, giving him command of four legions. The term of his governorship, and thus his immunity from prosecution, was set at five years, rather than the usual one. When his consulship ended, Caesar narrowly avoided prosecution for the irregularities of his year in office, and quickly left for his province.  Caesar was still deeply in debt, but there was money to be made as a governor, whether by extortion or by military adventurism. Caesar had four legions under his command, two of his provinces bordered on unconquered territory, and parts of Gaul were known to be unstable. Some of Rome's Gallic allies had been defeated by their rivals at the Battle of Magetobriga, with the help of a contingent of Germanic tribes. The Romans feared these tribes were preparing to migrate south, closer to Italy, and that they had warlike intent. Caesar raised two new legions and defeated these tribes.  In response to Caesar's earlier activities, the tribes in the north-east began to arm themselves. Caesar treated this as an aggressive move and, after an inconclusive engagement against the united tribes, he conquered the tribes piecemeal. Meanwhile, one of his legions began the conquest of the tribes in the far north, directly opposite Britain. During the spring of 56 BC, the Triumvirs held a conference, as Rome was in turmoil and Caesar's political alliance was coming undone. The Lucca Conference renewed the First Triumvirate and extended Caesar's governorship for another five years. The conquest of the north was soon completed, while a few pockets of resistance remained. Caesar now had a secure base from which to launch an invasion of Britain.  In 55 BC, Caesar repelled an incursion into Gaul by two Germanic tribes, and followed it up by building a bridge across the Rhine and making a show of force in Germanic territory, before returning and dismantling the bridge. Late that summer, having subdued two other tribes, he crossed into Britain, claiming that the Britons had aided one of his enemies the previous year, possibly the Veneti of Brittany. His intelligence information was poor, and although he gained a beachhead on the coast, he could not advance further, and returned to Gaul for the winter. He returned the following year, better prepared and with a larger force, and achieved more. He advanced inland, and established a few alliances. However, poor harvests led to widespread revolt in Gaul, which forced Caesar to leave Britain for the last time.  While Caesar was in Britain his daughter Julia, Pompey's wife, had died in childbirth. Caesar tried to re-secure Pompey's support by offering him his great-niece in marriage, but Pompey declined. In 53 BC Crassus was killed leading a failed invasion of the east. Rome was on the brink of civil war. Pompey was appointed sole consul as an emergency measure, and married the daughter of a political opponent of Caesar. The Triumvirate was dead.  Though the Gallic tribes were just as strong as the Romans militarily, the internal division among the Gauls guaranteed an easy victory for Caesar. Vercingetorix's attempt in 52 BC to unite them against Roman invasion came too late. He proved an astute commander, defeating Caesar in several engagements, but Caesar's elaborate siege-works at the Battle of Alesia finally forced his surrender. Despite scattered outbreaks of warfare the following year, Gaul was effectively conquered. Plutarch claimed that during the Gallic Wars the army had fought against three million men (of whom one million died, and another million were enslaved), subjugated 300 tribes, and destroyed 800 cities.  While he was still campaigning in Spain, the Senate began bestowing honours on Caesar. Caesar had not proscribed his enemies, instead pardoning almost all, and there was no serious public opposition to him. Great games and celebrations were held in April to honour Caesar's victory at Munda. Plutarch writes that many Romans found the triumph held following Caesar's victory to be in poor taste, as those defeated in the civil war had not been foreigners, but instead fellow Romans. On Caesar's return to Italy in September 45 BC, he filed his will, naming his grandnephew Gaius Octavius (Octavian, later known as Augustus Caesar) as his principal heir, leaving his vast estate and property including his name. Caesar also wrote that if Octavian died before Caesar did, Decimus Junius Brutus Albinus would be the next heir in succession. In his will, he also left a substantial gift to the citizens of Rome.  During his early career, Caesar had seen how chaotic and dysfunctional the Roman Republic had become. The republican machinery had broken down under the weight of imperialism, the central government had become powerless, the provinces had been transformed into independent principalities under the absolute control of their governors, and the army had replaced the constitution as the means of accomplishing political goals. With a weak central government, political corruption had spiralled out of control, and the status quo had been maintained by a corrupt aristocracy, which saw no need to change a system that had made its members rich.  Between his crossing of the Rubicon in 49 BC, and his assassination in 44 BC, Caesar established a new constitution, which was intended to accomplish three separate goals. First, he wanted to suppress all armed resistance out in the provinces, and thus bring order back to the Republic. Second, he wanted to create a strong central government in Rome. Finally, he wanted to knit together all of the provinces into a single cohesive unit.  The first goal was accomplished when Caesar defeated Pompey and his supporters. To accomplish the other two goals, he needed to ensure that his control over the government was undisputed, so he assumed these powers by increasing his own authority, and by decreasing the authority of Rome's other political institutions. Finally, he enacted a series of reforms that were meant to address several long-neglected issues, the most important of which was his reform of the calendar.

Did he cause his own demise