The Battle of Myonessus took place in September 190 BC. It was fought as part of the Roman–Seleucid War, pitting the fleets of the Roman Republic led by Admiral Lucius Aemilius Regillus and its Rhodian allies under Eudamus against a Seleucid fleet of Polyxenidas. Polyxenidas attacked his adversaries as they were putting to sea between Myonessus and the Corycus peninsula. The Roman–Rhodian fleet withstood the first assault, managing to assume battle formation. Eudamus then led the Rhodian squadron to the right flank of the Romans, thwarting a Seleucid attempt at encirclement and overpowering the Seleucid seaward wing. Polyxenidas withdrew, having lost half of his fleet. The battle cemented Roman control over the Aegean Sea, enabling them to launch an invasion of Seleucid Asia Minor. Background Following his return from his Bactrian (210–209 BC) and Indian (206–205 BC) campaigns, the Seleucid King Antiochus III the Great forged an alliance with Philip V of Macedon, seeking to jointly conquer the territories of the Ptolemaic Kingdom. In 198 BC, Antiochus emerged victorious in the Fifth Syrian War, taking over Coele-Syria and securing his south-eastern border. He then focused his attention on Asia Minor, launching a successful campaign against coastal Ptolemaic possessions. In 196 BC, Antiochus used the opportunity of Attalus I's death to assault cities controlled by the Attalid dynasty of Pergamon. Fearing that Antiochus would seize the entirety of Asia Minor, the independent cities Smyrna and Lampsacus decided to appeal for protection from the Roman Republic. In the early spring of 196 BC, Antiochus' troops crossed to the European side of the Hellespont and began rebuilding the strategically important city of Lysimachia. In October 196 BC, Antiochus met with a delegation of Roman diplomats in Lysimachia. The Romans demanded that Antiochus withdraw from Europe and restore the autonomous status of Greek city states in Asia Minor. Antiochus countered by claiming that he was simply rebuilding the empire of his ancestor Antiochus II Theos and criticized the Romans for meddling in the affairs of Asia Minor states, whose rights were traditionally defended by Rhodes. In late winter 196/195 BC, Rome's erstwhile chief enemy, Carthaginian general Hannibal, fled from Carthage to Antiochus' court in Ephesus. Despite the emergence of a pro-war party led by Scipio Africanus, the Roman Senate exercised restraint. The Seleucids expanded their holdings in Thrace from Perinthus to Maroneia at the expense of Thracian tribesmen. Negotiations between the Romans and the