Philip V of Macedon vs Theodosius I

Philip V allied with Carthage after Rome's defeat at Cannae, initiating the First Macedonian War against Rome. The war was indecisive, ending with the Peace of Phoenice in 205 BC, but it set the stage for future conflicts.

Philip V's Macedonian phalanx was decisively defeated by the Roman legions under Titus Quinctius Flamininus at Cynoscephalae. This battle ended the Second Macedonian War, forced Macedon to surrender its Greek possessions, and established Roman dominance in Greece.

After Cynoscephalae, Philip V signed the Treaty of Tempe, agreeing to pay war reparations, surrender his fleet, and withdraw from all Greek cities. He was allowed to keep Macedon but became a Roman ally, ending Macedonian expansion.

Theodosius I issued the Edict of Thessalonica, declaring Nicene Christianity the official state religion of the Roman Empire. All other forms of Christianity were deemed heretical, and pagan practices were increasingly suppressed.

Theodosius I ordered a massacre of thousands of citizens in Thessalonica in retaliation for the murder of a Roman general. The massacre led to his excommunication by Bishop Ambrose of Milan, and he later performed public penance.

Theodosius I issued a series of laws banning pagan worship, closing temples, and prohibiting sacrifices. The Olympic Games were abolished, and the Serapeum in Alexandria was destroyed. These actions accelerated the decline of paganism in the empire.

Theodosius I defeated the usurper Eugenius and his general Arbogast at the Battle of the Frigidus (modern River Vipava). The victory reunited the Roman Empire under a single ruler for the last time before its permanent division.

Upon his death, Theodosius I divided the Roman Empire between his two sons: Arcadius received the Eastern Empire and Honorius the Western Empire. This division became permanent, leading to the separate histories of the Byzantine and Western Roman Empires.