Short answers, pulled from the story.
Catiline, born Lucius Sergius Catilina around 108 BC, was a Roman patrician politician and soldier best known for instigating the Catilinarian conspiracy of 63 BC - a failed attempt to seize control of the Roman state by force. He was killed at the Battle of Pistoria in January 62 BC after his rebellion collapsed.
The Catilinarian conspiracy was a plot hatched in 63 BC, after Catiline lost the consular elections twice, to take the consulship by armed force. It involved planned assassinations, arson in Rome, and an armed uprising in Etruria led by an ex-Sullan centurion named Gaius Manlius. Consul Cicero uncovered the plot through anonymous letters delivered by Crassus and delivered his famous series of speeches, the Catilinarians, exposing it.
Catiline died at the Battle of Pistoria, fought near modern-day Pistoia in Tuscany, in early January 62 BC. His army, reduced to perhaps a few more than three thousand men, was defeated by republican forces under Marcus Petreius, who broke through the rebel centre with the praetorian cohort. Catiline was found dead far in advance of his own men, surrounded by enemy dead.
Cicero attacked Catiline in four speeches known as the Catilinarians, accusing him of murder, corruption, and planning to massacre Rome's leading politicians - though Cicero elsewhere praised Catiline's qualities as a general and motivator. Sallust, writing around the time of the Second Triumvirate, portrayed Catiline as a symbol of the Roman Republic's moral decline and coined the phrase vastus animus, meaning a ravaged mind, to describe his character.
Catiline belonged to the gens Sergia, an ancient patrician family that claimed descent from Sergestus, a Trojan companion of Aeneas. Despite this distinguished lineage, no member of the gens Sergia had held the consulship since 429 BC. His father was poor by aristocratic standards, and Catiline built his early wealth by profiteering during Sulla's proscriptions in 82 BC.
Catiline has inspired works across many centuries. Ben Jonson wrote Catiline His Conspiracy in 1611, depicting him as a sadistic anti-hero. Henrik Ibsen's first play, Catiline, written after the 1848 revolutions, cast him as a heroic figure. Antonio Salieri composed the opera Catilina in 1792, which remained unperformed until 1994. Francis Ford Coppola's 2024 film Megalopolis transplanted the conspiracy into a fictionalised futuristic America, with Adam Driver playing the Catiline figure.