The past century had seen the Greek world dominated by the three primary successor kingdoms of Alexander the Great's empire: Ptolemaic Egypt, Macedonia and the Seleucid Empire. In 202 BC, internal problems led to a weakening of Egypt's position, thereby disrupting the power balance among the successor states. Macedonia and the Seleucid Empire agreed to an alliance to conquer and divide Egypt. Fearing this increasingly unstable situation, several small Greek kingdoms sent delegations to Rome to seek an alliance. The delegation succeeded, even though prior Greek attempts to involve Rome in Greek affairs had been met with Roman apathy. Our primary source about these events, the surviving works of Polybius, do not state Rome's reason for getting involved. Rome gave Philip an ultimatum to cease his campaigns against Rome's new Greek allies. Doubting Rome's strength (a reasonable doubt, given Rome's performance in the First Macedonian War) Philip ignored the request, and Rome sent an army of Romans and Greek allies, beginning the Second Macedonian War. Despite his recent successes against the Greeks and earlier successes against Rome, Philip's army buckled under the pressure from the Roman-Greek army. In 197 BC, the Romans decisively defeated Philip at the Battle of Cynoscephalae, and Philip was forced to give up his recent Greek conquests. The Romans declared the "Peace of the Greeks", believing that Philip's defeat now meant that Greece would be stable. They pulled out of Greece entirely, maintaining minimal contacts with their Greek allies.
In what year did Philip lose the Battle of Cynoscephalae?
197 BC