See Trapani guide for highlights and historic monuments
Like Segesta, Eryx was a stronghold of the Elymi, and at the foot of Mount Eryx there was "Drepana" (later Trapani, see etymology further down) which was the first military port of the Carthaginians.
After the Roman conquest it became a port of only minor importance, at least until the advent of the Arabs, who developed it, making it one of the most important ports of Sicily. The Roman conquest of Eryx and Drepana was very difficult and Polybius (206-124 BC) said that the Romans conquered "totam Siciliam praeter Drepana” (trans: 'all Sicily, except Trapani'). 
In effect, with regard to the ancient fortification works of Trapani, M. Buscaino wrote:
“ […] Trapani appeared to the Ancients as a large castle with a more or less square shape, equipped with massive walls, ramparts, narrow and short streets. It was equipped with four towers, three inside and one in the ‘Castello di Mare’, located on the ‘Peliade’ island, now called ‘Colombaia’, reinforced from time to time until it assumed its present form...
...This castle was built by the inhabitants of Trapani as a defense to prevent any attack during the war between Carthage and the Syracusans of Colone, in 480 BC. The Carthaginian Hamilcar, during the Punic wars, built the “Castello di Terra” to the northeast of the city, fortified every point of defense, and added another four towers at each corner of the walls and garrisoned the Peliade island” 
After the Romans...
After the Roman age, the sources about Trapani are very fragmented. According to F. Maurici, the written and archaeological sources are missing . In essence, with regard to the late antiquity, the Byzantine, Norman and Arab period the sources are pratically silent.
Despite the lack of information, we do know something, though with many uncertainties. For example, it seems that Trapani was a Byzantine bishopric of some significance, but it is far from certain.
Arab and Norman era in Trapani
Trapani was conquered by Roger I [1031-1101): “Therefore, the following year (1077) [Roger I] reduced Trapani in his power with twelve castles" . Also with regard to the Arab age the sources are incomplete, but in this period major changes took place in the productive sectors, specially in agriculture. The name also changed, and Drepana became, in the years of Arab rule, "Tarabanis" or "Atrabanis" .
Although some cities, less populous than Trapani, were mentioned by the Arab chroniclers, in the case of Trapani the Arab author make no mention of it, and this, according to Maurici, was presumably due to the fact that Trapani was not involved in military events of importance, and during the Arab conquest the city surrendered and paid tribute.
In reality the city, from Byzantine times, experienced a slow decline. The Arabs rebuilt it, giving it a strong economic impulse that became a reality with the construction of local markets, public baths and thermae, while, in a climate of substantial mutual tolerance, new churches and mosques were built:
"Within the city there were markets and public baths fed by thermal and mineral waters, which, according to P. Benigno ("Trapani Profana”, 1810), were discovered at the beach of San Giuliano. There were mosques and churches built by Muslims, Jews and Christians, who were all living peacefully together and supporting each other. The cost of living was low, due to the frequent maritime traffic which allowed the purchase of cheap goods" .
Al Idrisi (1099-1166), writing in the Norman period, described Trapani as a very affluent city:
"[...] Trapani, a very old city, is situated near the sea that surrounds it on all sides; you can not enter except across a bridge to the east. The port is on the south side; it is a quiet port, and here there are a large number of vessels wintering safe from all winds. In this port is fished an overflowing quantity of fish and tuna. From the sea of Trapani is also taken a top-quality coral, and in front of the City Gate there is a saltern. The area is large and broad, with very fertile land, suitable for any type of seed and from which many products are made, and a great wealth. Trapani has convenient markets, and offers an abundance of the means of subsistence [...]" .
Entering the Middle Ages
With regard to the Middle Ages, the War of the Vespers was essential for the development of the city, especially for the fortifications - the walls were expanded and a new castle was built called the "Castello di Terra." It was built near the coast, and according to the typical forms of construction of Frederick II’s castles (with the rectangular and corner towers) .
Another important castle among the fortifications of Trapani was the so-called “Torre della Colombaia”, an octagonal donjon. The name of “Colombaia” is based on the doves nesting on the rocks or maybe the doves dedicated to the goddess Venus, whose temple was situated on the famous Mount Eryx . The date of construction of the "Torre della Colombaia" is uncertain, but presumably dates back to the War of the Vespers .
James II of Aragon (1267-1327) in 1286 implemented the expansion of the city and the reclamation of the surrounding land, on which there arose new building areas, which were enclosed within wider walls (which in the late16th century underwent a new restoration work).
In the 13th century, when the Franciscan Fathers settled in Trapani, the city already had a defined structure:
"The original village of the Elymi, formed around the port, is already a city urbanistically configured. It has a square structure , fortified, and is bounded by sea to the north and south and by reefs and islands to the west (the district called “Palazzo”), and is linked to its territory to the east.
Inhabited by different ethnic groups in its two areas of “San Pietro” and “Mezzo”, Trapani is characterized by the robust activity of the merchants, whose immigration was favored by Roger I, with the dual aim of increasing Christian population and to strengthen its economic activities (...) Some Merchants of Lucca and the French built inside the walls to the south-east (...); the Catalans, Genoese, and Florentines located their commercial activities outside the walls" .
To this description we can add that Trapani had a fervent religious life, with the arrival of religious orders like the Dominicans, Carmelites and Franciscans.
Arrival of the Spanish
Spanish rule of Trapani began in the 15th century, and this period was characterized by frequent pirate raids, which imposed the creation along the coast and the Sicilan hinterland of a defense system with towers and castles. This function was also performed by the “Castello della Colombaia”.
In the second half of the 17th century the tower called "Ligny" was also erected, named by the Spanish viceroy Claudio Lamoraldo. In reality, Trapani, because of its geographical position, was very vulnerable to piracy, because at close range there is Favignana, which offered a safe hiding place for pirate ships, who could easily control the movement of ships in the port of Trapani .
The ships that came from Trapani were an irresistible attraction for pirates, because of the volume of trade with Tunis, and especially the commercial environment of Trapani, which consisted predominantly of Jews:
"[...] The Kings of Sicily were conscious of the close connection between Sicily and the coast of Tunisia; King Martin I (1374-1409) before and then Alfonso V (1394-1458), tried therefore through diplomatic channels to ratify an intense relationship of economic exchanges [... ] " .
Trapani from the 18th century
The Spanish domination of Trapani was replaced by that of the Savoy in 1713, then by the Austrians in 1720 and finally by the Bourbons in 1738, which ushered in a period of peace.
This peace lasted until the political movements for national unification, and allowed the city to take an important role as a trading centre of agriculture and fishing and led also to the reclamation of the area west and urban development. Trapani entered the Kingdom of Italy with the National Unification in 1861.
In the last decades of the 19th and in early 20th century Trapani became the sixth port of Italy and an important industrialized region linked to the manufacture of salt and fishing for tuna, activities that still exist today along with agriculture, which is characterized by the production of wheat, prized grapes and olives.
Also significant are the marble industry and especially the activities related to the conservation of flora and fauna, with a view to a strong revival of the tourism industry and related services related.
Etymology of the name Trapani
We usually read that Trapani derives from "Drepanon" which means "sickle." This, in itself, is essentially correct, but frequently it involves some confusion because the names "Drepanon", "Drepana", and "Drepane" are very common among place names in the Mediterranean area.
Strictly speaking the etymology of Trapani comes more from "Drepanon" [singular = the sickle] than would derive from "Drepana" [plural = the sickles]. Which might seems meaningless, but instead the difference is significant because it involves a different perspective on the history of Trapani...
In the 4th century BC Trapani was the port of Eryx, then as a city Trapani arose during the First Punic War, in which Hamilcar Barca (275-228 BC) occupied Eryx. Because he did not feel confident that he could retain because of people suspected of having sympathies with the Romans, he evacuated it and transported the inhabitants towards the sea.
The port abandoned the former name of “Emporium of the ‘Ericini’” re-naming itself “Drepana” = the sickles. G. De Sanctis, writing about the antiquity of Trapani and its plural name, wrote: "Drepana with this name does not appear before the First Punic War, and indeed (...) before 249, when the Carthaginians reinforced it and moved here the people of Eryx (...) It was called 'Drepana' by all ancient Greek and Latin writers, and “Drepanon” [singular] appeared only in Callimachus (305-240 BC) and Ptolemy (100-175 AD) .
According to L. Antonelli  the myth of the "sickle" was "imported" by the Euboeans and Phoceans, who arrived in western Sicily in pre-colonial times (10th-7th century BC), not only to get in touch with the local people and the Phoenician merchants, "but also to have a base towards the coasts of Tunisia"
The Euboeans were the first to arrive in the West . They came from the cities of Chalcis and Eretria, on the island of Euboea, and situated in the Aegean Sea off the coast of Attica. According to Herodotus, the Phoceans were the first Greeks to undertake long journeys and to discover the Adriatic Sea, the Thyrrenia and Iberia.
Therefore the Phoceans arrived in Sicily in very ancient times, coming into contact with the Sikans. According to L. Antonelli it was the Phoceans that "first may have defined the indigenous people as “Elymi”, inspired by the fact that they used to eat the millet (in Greek called “elymos”).
The relationship between the millet [“elymos”] and the name of the Elymi is owed to G. Nenci  who said the Elymi came from Phrygia, landing in Calabria and finally settling in Sicily.
The Myth of the sickle...
Through the trades that occurred with Zancle ('Messina', the etymology of which is similarly the “sickle”) and Drepana (Trapani), the Euboean and Phocean merchants thus brought to Sicily the "myth of the sickle" , Graecizing the Sikan term "Zancle" (Messina) with Drepanon.
Thanks to this "importation" of the “sickle” idea, the Greeks combined their myths relating to Saturn’s and Demeter's sickle. The first legend has it that Saturn, having mutilated his father Uranus, flung aside the sickle, after which the site was called "Drepanos"; the second legend tells that Demeter-Ceres lost the sickle (the symbol of fertility of the Sicilian soil) while looking for his daughter Persephone. Which of these two legends would be suitable for Trapani?
Generally, scholars are convinced that the sickle or sickles of Trapani refer to the myth of Saturn: “The sickle was invoked to explain the origin of at least two other place names, relating to Drepane-Corcyra and Zancle-Messana [Messina]; we must add to these Drepanon in Sicily, that is the current Trapani, and Drepane in Bithynia (in both cases the reference is to the sickle of Kronos-Saturn) .
About this Ettore Pais wrote: "Thus we see that the myth of the sickle is both closely connected with the foundation of Zancle (Messina, “the sickle”) and of Drepanon (Trapani) (...) Drepanon of Sicily is also known as 'Kronion'. This is the famous myth of Cretan origin or of the Phoenician god Kronos (later assimilated to the Roman god Saturn). " 
See also Trapani for destination information and a detailed travel guide.
1. See G. De Sanctis, “Gli ecisti di Messina e Callimaco”, in “Scritti minori”, pp . 44-45 ff.
2. See L. Antonelli, “Euboici e Focei nella terra degli Elimi?”, in “Traffici focei di età arcaica: dalla scoperta dell'Occidente alla battaglia del mare Sardonio”, Rome, 2008, p. 58
3. “L'ethnos 'Elymos' e il ruolo del panico nell'alimentazione antica”, in "ASNP", 1989, 19, 1255 ff.
4. Antonelli (ref 2 above), p. 69
5. [Pfeiffer, "Kallimachosstudien", Wilamowitz, ‘Hell. Dicht.’, Ehlers, Fraser] See G. Massimilla, “Aitia: libri primo e secondo: introduzione, testo critico, traduzione e commento”, [" Aitia: First and Second Books. Introduction, Critical Text, Translation and Commentary "], Giardini, 1996, p. 266
6. See E. Pais, “Storia dell' Italia antica e della Sicilia per l'età anteriore al dominio romano”, 1933 , p. 293
7. See "Polybii Licortae”, 1670, p. 60
8. See M. Buscaino, “Torri, castelli e fortificazioni in Trapani”, in “Il Galeone”, Messina, 1988, p. 14
9. See Godfrey Malaterra (11th century) in J.G. Wenrich, “Rerum ab Arabibus in Italia insulisque adjacentibus: Sicilia maxime, Sardinia atque Corsica gestarum commentarii”, 1845, p. 203
10. See F. Maurici, “ “Per la storia delle città siciliane in età islamica”, in “Memoria, storia e identità…”, Palermo, Mediterranea, p. 521
11. See M. Serraino, “La dominazione araba”, in “Storia di Trapani”,[" The Arab domination ", in" History of Trapani”], 1976, p. 46
12. See M. Amari, "Edrisi," in "Biblioteca Arabo-Sicula", Rome, Loescher, 1880, Vol I, pp. 79-80
13. See Maurici, pp. 528-534
14. See G.A. Massa, "La Sicilia in Prospettiva", 1709, pp. 429-430
15. See F. Maurici, “ Le difese costiere della Sicilia”, in “Zones côtières littorales dans le monde méditerranéen au Moyen Âge: défense, peuplement, mise en valeur” , 2001, pp. 188-189
16. See A.I. Lima, “Conventi francescani a Trapani …”, in “Francescanesimo e cultura in Sicilia. Secc. XII-XVI”, Officina di studi medievali, 1982, pp. 327 ff.
17. About the presence of pirates at Trapani, See H. Bresc, “Course et piraterie en Sicile”, in “Anuario de estudios Medievales”, 1980, 10, p. 756
18. See, G. Costantino, “Le relazioni degli ebrei trapanesi con il regno hafside di Tunisi sotto Alfonso V”, in “Mediterranea”, 2008, p. 519