The Battle of Orchomenus was fought in 85 BC between Rome and the forces of Mithridates VI of Pontus. The Roman army was led by Lucius Cornelius Sulla, while Mithridates' army was led by Archelaus. The Roman force was victorious, and Archelaus later defected to Rome. Information on the battle is included in Plutarch's Life of Sulla, chapters 20-21.