The war began with the Romans landing on Sicily in 264 BCE. Despite the Carthaginian naval advantage, the Roman crossing of the Strait of Messina was ineffectively opposed. Two legions commanded by Caudex marched to Messana, where the Mamertines had expelled the Carthaginian garrison commanded by Hanno (no relation to Hanno the Great) and were besieged by both the Carthaginians and the Syracusans. The sources are unclear as to why, but first the Syracusans, and then the Carthaginians withdrew from the siege. The Romans marched south and in turn besieged Syracuse, but they had neither a strong enough force nor the secure supply lines to prosecute a successful siege, and soon withdrew. The Carthaginians' experience over the previous two centuries of warfare on Sicily was that decisive action was impossible; military efforts petered out after heavy losses and huge expense. The Carthaginian leaders expected that this war would run a similar course. Meanwhile, their overwhelming maritime superiority would allow the war to be kept at a distance, and even for them to continue to prosper. This would allow them to recruit and pay an army that would operate in the open against the Romans, while their strongly fortified cities could be supplied by sea and provide a defensive base from which to operate.