In 275 BC, the Syracusan army and citizens appointed Hiero commander-in-chief after Pyrrhus of Epirus left Sicily. He strengthened his position by marrying the daughter of Leptines, one of the leading citizens of Syracuse. This union connected him to powerful local families and secured political support within the city. Hiero later proved his military worth against the Mamertines, a body of mercenaries from Campania who had seized Messina as a base of operations. They harassed the Greeks around them until Hiero defeated them in a pitched battle near Mylae along the Longanus river. Carthaginian interference prevented him from capturing Messina itself, but he gained control over much of the territory. Between 275 and 271 BC, he seized total power in the city by allying himself with the people. Unlike past kings or tyrants of Syracuse, he ruled within the law and acknowledged the will of the assemblies. He never purged his opponents, which allowed him to maintain stability while consolidating authority.
First Punic War Alliances
Hiero was proclaimed king after a victory in 265 BC when fighting the Mamertines prior to the formal start of the First Punic War. The next year, the Mamertines became desperate and called for Roman aid. Hiero at once joined the Punic leader Hanno, who had recently landed in Sicily. Fighting a battle to an inconclusive outcome with the Romans led by the consul Appius Claudius Caudex, he withdrew to Syracuse. Pressed by the Roman forces, in 263 BC he concluded a treaty with Rome. By this agreement, he was to rule over the south-east of Sicily and the eastern coast as far as Tauromenium. This diplomatic shift marked a turning point in regional politics during the conflict. His alliance with Rome proved crucial for maintaining Syracuse's autonomy while other cities fell under Carthaginian control. The treaty established boundaries that would define Syracuse's territory for decades to come.Archimedes And Defense