Denominazione che assunsero quali “figli di Mamerte” - nome osco del dio della guerra corrispondente al Marte romano - i mercenari campani, assoldati da Agatocle, tiranno di Siracusa. Dopo la morte di questo, nel 289 aC, si impadronirono di Messina con scorrerie e saccheggi compiuti nel territorio circostante e nel Bruzzio (donde però furono cacciati dai Romani). Per liberarsi da una guarnigione cartaginese chiamata nel 263 in aiuto contro i Siracusani di Gerone II, i Mamertini si rivolsero ai Romani, i quali, passato lo stretto nel 264, misero piede sul suolo siciliano dando inizio al secolare conflitto con Cartagine.
I Mamertini (cioè figli di Marte) erano dei soldati mercenari d'origine per lo più campana arruolati tra la fine del IV e gli inizi del III secolo aC da Agatocle, tiranno di Siracusa. Alla morte di quest'ultimo nel 289 aC, la maggior parte dei Mamertini, rimasti senza lavoro, tornarono in patria, mentre altri rimasero nell'isola. Alcuni di loro si impadronirono a tradimento della città greca di Messina, ubicata sullo stretto in una posizione di grande importanza strategica. Dopodiché assunsero il nome di Mamertini da Mamerte, divinità osca della guerra, paragonabile al romano Marte.
Il loro dominio durò oltre 20 anni, durante i quali trasformarono Messina da centro agricolo e commerciale a base per le loro scorrerie piratesche sia sul mare CHE sulla terraferma. L'errore per loro fatale fu quando rivolsero la propria attenzione alla città di Siracusa. Nel 270 aC il siracusano Ierone li sconfisse in battaglia nei pressi di Milazzo. Dopodiché si preparò ad assediare Messina (265 aC). A questo punto i Mamertini chiesero l'aiuto di Cartagine che occupò il porto della città. I Siracusani si ritirarono. Ma i Mamertini, che volevano scrollarsi di dosso l'ingombrante presenza cartaginese, chiesero aiuto a Roma, facendo leva sulla comune origine italica e sulla discendenza di entrambi i popoli da Marte. A loro favore intervenne Appio Claudio Caudice. La presa di posizione di Roma a favore dei Mamertini provocò lo scoppio della Prima Guerra Punica (264 a.C.), nella quale, comunque, i Mamertini non sono ricordati da nessuna fonte.
The Mamertines (Mamertini "sons of Mars") were mercenaries of Italian origin who had been hired from their home in Campania by Agathocles, the king of Syracuse. After Syracuse lost the Third Sicilian War, the city of Messene was ceded to Carthage in 307 BC. When Agathocles died in 289 BC he left many of his mercenaries idle and unemployed in Sicily. Most of them returned home but some liking the climate and the prospect of adventure on a foreign island remained. They played a major role in the lead up to the First Punic War.
In 280 BC, the Mamertines appealed to King Pyrrhus of Epirus for help. During this time, Rome began expanding into Magna Graecia, and they also appealed for help. This action sparked the Pyrrhic War. Pyrrhus was proclaimed king of Sicily and began his fight against the Carthaginians, in which he scored several great victories. Pyrrhus, though a great commander, mistreated the Sicilians, who quit supporting Pyrrhus. After a few great victories, Pyrrhus abandoned his campaign and left for the states of Southern Italy, who also appealed to him for help. Pyrrhus fought, but eventually returned to Epirus after the Battle of Beneventum (275 BC).
Capture of Messana
The then small band of desperados came across the walled Greek settlement of Messana (now Messina). Messana was a strategic point, built on the north-eastern tip of Sicily and it with the fort Rhegium on the toe of Italy, were the crossing points of the straits between Italy and Sicily. Being a peaceful people, the inhabitants allowed the travelling mercenaries into their homes. After a time, the mercenaries became restless and plotted to capture the town. One night, the mercenaries betrayed their hosts and killed most of the population who were unprepared. In this way, they claimed Messana for themselves. The surviving Messanians were thrown out and the property and women divided. After their victory, the mercenaries named themselves the Mamertines after the Oscan war-god Mamers.
Dominion over north-eastern Sicily
The Mamertines held the town of Messana for over 20 years. They changed it from being a bustling town of farmers and traders to a raiding base. The Mamertines became pirates on land and sea. Taking advantage of the peacefulness of the Sicilians they looted the nearby settlements and captured unwary trade ships on the strait, carrying their plunder back to their base. They captured prisoners and demanded tribute. During this period, they struck coins on which their name is printed and images of their gods and goddesses. Their exploits made them rich and powerful. They began travelling further inland, even as far as Gela.
The Mamertine presence did not go unchallenged forever. In around 270 BC, the Mamertine exploits came to the attention of Syracuse, by word of the refugees from the settlements. Hiero II of Syracuse began to gather an army of citizens with which to rid the land of the destroyers of the peace and rescue his Greek kinsmen.
Hiero met with the Mamertines when they were nearing Syracuse. Marching out his troops, he first sent his unruly mercenaries forward and allowed them to be butchered by the Mamertines. The faithless part of his army disposed of, Hiero marched his citizen soldiers back to the city where he drilled them to a better fighting condition. Leading his confident army north, he found the Mamertines again at the Longanus River on the plain of Mylae where he easily defeated them, since the Mamertines were not accustomed to large pitched battles and had become reckless after beating Hiero's mercenaries. In the battle, Hiero captured the Mamertine leaders and the remnants fled back to the safety of Messana. Hiero had restricted the Mamertine activity and placed them in a dire situation.
When Hiero returned to besiege their base (Messana) in 265 BC the Mamertines called for help from a nearby fleet from Carthage, which occupied the harbor of Messana. Seeing this, the Syracuse forces retired, not wishing to confront Carthaginian forces. Uncomfortable under the Carthaginian "protection," the Mamertines now appealed to Rome to be allowed into the protection of the Roman people. At first, the Romans did not wish to come to the aid of soldiers who had unjustly stolen a city from its rightful possessors. However, unwilling to see Carthaginian power spread further over Sicily and get too close to Italy, Rome responded by entering into an alliance with the Mamertines. In response, Syracuse allied itself with Carthage, imploring their protection. With Rome and Carthage brought into conflict, the Syracuse/Mamertine conflict escalated into the First Punic War.
Ironically, once the scale of the conflict had escalated beyond them, the Mamertines were lost to the historical record and their fate is lost, swallowed up in the larger events of the Punic wars.
After the First Punic War, the Mamertines are lost to history, although their name was not quite forgotten in the ancient world since "Mamertine wine" from the vineyards of north-eastern tip of Sicily was still known and enjoyed in the first century. It was the favourite of Julius Caesar and it was he who made it popular after serving it at a feast to celebrate his third consulship. Even centuries after the Mamertine occupation, the inhabitants of Messana were still called Mamertines.
In his novel Salammbô, Gustave Flaubert writes of the Greeks singing the 'old song of the Mamertines': "With my lance and sword I plough and reap; I am master of the house! The disarmed man falls at my feet and calls me Lord and Great King."