The second Roman campaign of the First Punic War saw a dramatic change in the balance of power on Sicily. During the campaign of 264 B.C. the Romans had faced an alliance between Carthage and Hiero II of Syracuse. The Roman aim for 263 seems to have been to knock Hiero out of the war. Both Consuls for the year were allocated to the expedition, taking with them four legions and associated allies, potentially giving them a force of around 40,000 men. The expedition against Syracuse was under the command of Marcus Valerius Maximus, later give the honorary cognomen “Messalla”.
The Roman army landed in the north east of Sicily, at Messana, the city they had gone to war to support. From there they marched south into Syracusan territory, capturing Hadranum, south of Mount Etna. As a result, a series of cities in the area submitted to Rome. From Hadranum the Romans moved to besiege Syracuse. The aim here was probably not to capture the city. Syracuse had some of the most impressive defences in the Ancient World, and could easily be supplied by sea. However, the alliance with Carthage was unpopular in Syracuse – the two powers had fought a series of wars for control of Sicily over the previous three centuries. Faced with direct evidence of Roman power, Hiero changed sides, negotiating an alliance with Rome.
The alliance was to run for fifteen years. Hiero would pay Rome 100 talents (twenty five immediately, the rest in fifteen installments). In return he was recognised as King of Syracuse. His kingdom extended for thirty miles inland from Syracuse. When the treaty expired it was replaced by a perpetual alliance, with no associated payments.
The alliance with Syracuse allowed the Romans to concentrate on a single enemy. It also provided their ships with a safe haven at the south east corner of Sicily, which saved many Romans ships that might otherwise have been lost. Syracuse also became an important supplier of corn to the Roman armies campaigning on Sicily. Marcus Valerius Maximus was awarded a triumph for his achievements on Sicily in 263.