As displayed in Sicily, the triskelos, as the Greeks called it, features the head of Medusa at the centre of three conjoined, nude legs. In antiquity the Medusa was a generic gorgon's head.

The symbol appeared in the coinage of Greek Sicily. In the Syracusan gold piece shown here the feet are winged like those of Hermes (Mercury).

Despite its widespread numismatic use, the trinacria itself never became a heraldic symbol in Sicily. That is to say, it never appeared in a Sicilian coat of arms until very recently. Yet it was published in numerous official documents over the centuries.

By 1270, if not long before, a similar symbol became known as the heraldic insignia of the Isle of Man, sometimes simply called Mann. The difference from the Trinacria is that the Manx legs are armoured and accompanied by no other feature. There is no head.

It is believed - through an unproved theory - that this symbol was introduced on Mann during Plantagenet times. The Normans arrived in England at the Battle of Hastings in 1066, having landed at Messina five years earlier, and while they did not rule Mann their influence across Britain was significant. Although actual heraldry emerged only a century later, the Anglo-Normans are thought to have imported several symbols from their Sicilian counterparts, including the lion rampant displayed by the Norman kings of both realms. It has also been suggested that when young Prince Edmund was offered the Sicilian Throne in 1253 (it eventually went to Charles of Anjou, brother of Saint Louis) he may have begun to use the device. The Scots king, Alexander III, may have seen it during a visit to London and decided to assume it as the symbol of the Isle of Man, which was in his dominion. It is also possible that, in an earlier time, the Vikings introduced the Manx symbol following their raids in Sicily.

Back in Sicily, the trinacria sometimes appeared on coins. In 1302, with the treaty known as the Peace of Caltabellotta, an agreement sanctioned by the Papacy following decades of strife in the wake of the Vespers War of 1282, King Frederick III "the Simple" of Aragon (father of Queen Mary) was recognized as the ruler of Sicily if he styled himself "King of Trinacria," while his royal counterpart in Naples retained the nominal title "King of Sicily."

About the Author: Carlo Trabia is an architect who lectures on architectural history.