The siege of Athens and Piraeus was a siege of the First Mithridatic War that took place from Autumn of 87 BC to the Spring and Summer of 86 BC. The battle was fought between the forces of the Roman Republic, commanded by Lucius Cornelius Sulla Felix on the one hand, and the forces of the Kingdom of Pontus and the Athenian City-State on the other. The Greek Pontian forces were commanded by Aristion and Archelaus.

Lucius Cornelius Sulla Felix (; 138–78 BC), commonly known as Sulla, was a Roman general and statesman. He won the first large-scale civil war in Roman history and became the first man of the Republic to seize power through force.

Sulla had the distinction of holding the office of consul twice, as well as reviving the dictatorship. A gifted and innovative general, he achieved numerous successes in wars against foreign and domestic opponents. Sulla rose to prominence during the war against the Numidian king Jugurtha, whom he captured as a result of Jugurtha's betrayal by the king's allies, although his superior Gaius Marius took credit for ending the war. He then fought successfully against Germanic tribes during the Cimbrian War, and Italic tribes during the Social War. He was awarded the Grass Crown for his command in the latter war.

Sulla played an important role in the long political struggle between the optimates and populares factions at Rome. He was a leader of the former, which sought to maintain senatorial supremacy against the populist reforms advocated by the latter, headed by Marius. In a dispute over the command of the war against Mithridates, initially awarded to Sulla by the Senate, but withdrawn as a result of Marius' intrigues, Sulla marched on Rome in an unprecedented act and defeated Marian forces in battle. The populares nonetheless seized power once he left with his army to Asia. He returned victorious from the east in 82 BC, marched a second time on Rome, and crushed the populares and their Italian allies at the Battle of the Colline Gate. He then revived the office of dictator, which had been inactive since the Second Punic War, over a century before. He used his powers to purge his opponents, and reform Roman constitutional laws, to restore the primacy of the Senate and limit the power of the tribunes of the plebs. Resigning his dictatorship in 79 BC, Sulla retired to private life and died the following year.

Sulla's military coup was ironically enabled by Marius' military reforms that bound the army's loyalty with the general rather than to the republic and permanently destabilized the Roman power structure. Later political leaders such as Julius Caesar would follow his precedent in attaining political power through force.