I have had to speak more than once of mercenary troops employed by the Greek cities in Sicily to help them in their long struggle with Carthage. The use of such troops was a regular practice with Carthage; it was only on great occasions that this State put its own citizens in the field. With the Greeks, on the contrary, it was the exception to employ any but citizen soldiers. The mercenary was suspected, and not without reason, of being a ready instrument in the hands of any unscrupulous person who might be seeking to establish a tyranny. As time went on, however, he became more and more a necessity. As society became more complex, the citizen found himself less willing to bear arms and less capable of doing it. And the exhaustion caused by almost incessant wars made it necessary to seek elsewhere for men who should fill up the depleted ranks. Hence the employment of mercenaries even by free cities. Whatever their use in time of war, these auxiliaries were naturally difficult to manage or dispose of when peace had been restored.[14] Such certainly the Syracusans found to be the case with a body of Italian mercenaries whom Agathocles[15] had had in his service. They were paid off and peremptorily ordered to return home. This prospect was not agreeable; it meant a return to regular and not very profitable labour; they greatly preferred to live by the sword. They professed, however, to be willing to obey the command, and accordingly marched in the direction of Italy, intending, it appeared, to be ferried across the Straits of Messana. Whether they had fixed on any settled plan, or yielded to the sudden attraction of a chance that seemed to offer itself, cannot be determined. What we know is that when they reached Messana, from which they were to have embarked, and had been imprudently invited within the walls by its citizens, they seized the town with all that it contained. Here they established themselves, taking the name of _Mamertini_, or "Servants of Mars" (_Mamers_ was the Oscan name for the deity known to the Romans as _Mars_). A similar body held the adjacent mainland, and the two, joined as they were by an informal alliance of interests, became a formidable power. They practically lived by robbery by land and sea, and their existence became an intolerable nuisance to the two powers that shared Sicily between them. For once the interests of Syracuse and Carthage were identical. The Syracusan troops inflicted a severe defeat on the Mamertini, and, with the help of their new allies, closely besieged their town.