Trapani was founded by the Elymians to serve as the port of the nearby city of Erice (ancient Eryx), which overlooks it from Monte San Giuliano. The city sits on a low-lying promontory jutting out into the Mediterranean Sea. It was originally named Drépanon from the Greek word for "sickle", because of the curving shape of its harbour. Carthage seized control of the city in 260 BC, subsequently making it an important naval base, but ceded it to Rome in 241 BC following the Battle of the Aegates in the First Punic War.
Two ancient legends tell of mythical origins for the city. In the first legend, Trapani stemmed from the sickle which fell from the hands of the goddess Demeter while she was seeking for her daughter Persephone, who had been kidnapped by Hades. The second myth features Saturn, who eviscerated his father Uranus, god of the sky, with a sickle which, falling into the sea, created the city. In ancient times Saturn was the god-protector of Trapani. Today Saturn's statue stands in a piazza in the centre of the city.
After the Roman, Vandal, Byzantine and (from the 9th century) Arab dominations, Trapani was conquered by the Normans of Roger I, flourishing under their dominations and having also a role in the Crusades as one of the most important ports in the Mediterranean Sea. In the 17th century the city decayed due to revolts, plagues and famines; however in the following century it grew from 16,000 to 30,000 inhabitants; commerce remained of local importance, while its military position in the Kingdom of Naples remained notable.
The city was badly damaged during World War II when it was subjected to intense Allied bombardments. It has grown greatly since the end of the war, sprawling out virtually to the foot of Monte San Giuliano. Tourism has grown in recent years due to the city's proximity to popular destinations such as Erice, Segesta and the Egadi Islands