The magnificent natural harbour of Mahon has been the key to the city's historical, political and economic development. Built on the ruins of a prehistoric settlement, Mahon soon became an obligatory port of call in Mediterranean trade relations. Carthaginian, Phoenician and Greek sailors stopped there, some passing through and others intending to stay. In fact, it was the Carthaginian General Mago who bestowed the name of Mahon upon the city after his stay circa 200 A.C.. The city was declared a Roman municipality in the first century B.C., and later became part of the Byzantine Empire. During the island's Arab rule, Mahon went into a decline when the island's political centre was moved to Ciutadella. In 1287, Alfonso III returned part of its old prominence when he chose it as the port from which to launch the Christian conquest of the island.
In 1535, Mahon was captured by the dreaded pirate Barbarossa who razed the city almost entirely after a brief siege and treacherous pact with the local elite. These dramatic events compelled Philip II to begin the construction of Fort de Sant Felip which, in one of history's paradoxes, became a key element in the city's favour in its bid to become the island's capital over the years. In 1706, the governor of the Castle of Sant Felip was appointed Menorca's governor and in 1722 under British rule, Mahon officially became the island's new capital.
In the early 19th century, the city basked in a golden age that was the result of the significant wheat trade with the Black Sea. Nevertheless, restrictions on free trade imposed by the Spanish Crown in 1820 submerged the city in a new crisis which was partially solved by its growing industrial activity. In the mid-twentieth century, a new era opened up for Mahon, marked by the recovery of industry and the onset of the tourist phenomenon.