Sulla seized Rome by force, ruled as dictator, then simply resigned
No general of the late Republic before Lucius Cornelius Sulla had turned his legions on Rome itself and come out the winner. He purged his enemies, revived a dictatorship unused for over a century, rewrote the constitution, and then gave the power back. Pompey and Caesar learned the lesson of the march, not the resignation.
Sulla was born in 138 BC into a patrician branch of the Cornelii that had sunk into poverty. An ancestor, the family's last consul, had been expelled from the Senate for owning more than ten pounds of silver plate. After his father's death Sulla had little or nothing to inherit and spent his youth among actors, musicians and dancers, even writing the rough comic plays known as Atellan farces. Plutarch says those friendships, including a lifelong attachment to the actor Metrobius, never ended. A wealthy stepmother helped fund his ambitions.
War made him. Serving under Gaius Marius against the Numidian king Jugurtha, Sulla captured the king after his allies betrayed him, though Marius claimed the credit. He fought well against Germanic tribes in the Cimbrian War and against Rome's Italian allies in the Social War, winning the Grass Crown for bravery at Nola. He cultivated a link with Venus, calling himself Epaphroditos, favoured of Aphrodite.
As consul in 88 BC he was given command against Mithridates of Pontus, only to lose it through a deal between Marius and the tribune Publius Sulpicius. Sulla responded by leading his army into Rome, driving out Marius and his allies. While he was away beating Pontic armies at Chaeronea and Orchomenos in 86, Marius and Cinna returned, killed opponents and declared Sulla a public enemy. He made a generous peace with Mithridates, came home, and crushed their successors at the Colline Gate in 82.
In power he revived the dictatorship, dormant since the Second Punic War, and used proscription lists to destroy opponents. His reforms restored the Senate's primacy and curbed the tribunes of the plebs. At the start of 80 BC he stepped down, served an ordinary consulship that year, and then retired to private life. He died in 78 BC, leaving a precedent for using armies to win political power.
Source: Sulla