Ancient sources agree that Carthage had become perhaps the richest city in the world through its trade, yet very few traces of its wealth have been discovered by archaeologists. This is because most of it was in perishables--textiles, unworked metal, foodstuffs, and slaves; its trade in manufactured goods was only a part of the whole. There can be no doubt that the most profitable trade was that inherited from the Phoenicians in the western Mediterranean, in which tin, silver, gold, and iron were obtained in exchange for manufactures and consumer goods of small value. Carthage ruthlessly maintained its monopoly of this trade from the late 6th to the end of the 3rd century BC by sinking intruders and exacting recognition of its position from other states. Its wealth is attested by the vast mercenary armies it was able to maintain with a mintage of gold coins in the 4th century far in excess of that known for other advanced states.

It was apparently in connection with this trade that during the 5th century there occurred two voyages of exploration and trade, evidently of particular importance since reports of them were known to later generations of Greeks and Romans. One was along the Atlantic coast of Morocco, the other northward along the Atlantic coast of Spain. They were led by Hanno and Himilco, respectively, both members of a leading family in Carthage. Hanno's voyage is generally associated with an account in Herodotus, writing about 430 BC, of Carthaginian trade on the Atlantic coast of Morocco. Herodotus describes a system of dumb barter with the coastal peoples, by which the Carthaginians exchanged manufactured goods for gold. It is not known where the exchanges took place; the R�o de Oro is a possibility, and it is probable that Hanno's expedition went beyond Cape Verde. Nevertheless, the "gold route" did not survive the fall of Carthage and was not exploited by the Romans. This has led some scholars to argue that the Carthaginians' interest in the Atlantic coast of Morocco was stimulated by the more prosaic attraction of the abundant fish.

Himilco's voyage also was known to the Greeks and Romans. He sailed north along the Atlantic coast of Spain, Portugal, and France and reached the territory of the Oestrymnides, a tribe living in Brittany. The purpose of this voyage was apparently to consolidate control of the trade in tin along the Atlantic coast of Europe. It followed the route used by the Tartessians, a people of southern Spain, in the area where Cadiz had been founded, who knew of Ireland and Britain. This trade was no doubt the latest phase of contact between the various areas of the Atlantic seaboard that went back to late Neolithic times. There is no evidence that Himilco reached Britain, nor indeed has any Phoenician object ever been found on the island, but probably Cornish tin was obtained through the tribes of Brittany. Tin was also obtained from northwestern Spain. It is notable that, at C�diz, the Carthaginian tombs found at intervals there over the past century have produced nothing earlier than the 5th century, which would indicate that it was not until that date that C�diz became a large and permanent base for the exploitation of trading opportunities in the west.

Trading contacts with the Greek world had been substantial from the earliest period of Phoenician colonization, in spite of the intermittent wars with the Greeks of Sicily. Pottery from Corinth, Athens, Ionia, Rhodes, and other Greek centres has been found at Carthage, Utica, and many other sites, as well as imports from Phoenicia itself and from Egypt. It is known that Selinus, a Greek city in Sicily, grew wealthy from trade with Carthage, probably in foodstuffs, before Carthage enlarged its Sicilian territory. During the 5th century there appears to have been a decline in imports from the Greek world. One factor that may have inhibited trade was the lack of a Carthaginian coinage before the early 4th century, though most important Greek states had had their own coinages for at least a century before that. Carthaginian merchants, however, did not cease to frequent Greek ports, and a number of them were established at Syracuse in 398. From that date, economic contacts with advanced states seem to have revived, especially after the conquests of Alexander the Great in the eastern Mediterranean created a new market for the cheap Carthaginian manufactured goods. The Carthaginian merchant became a familiar figure in such economic centres of the Greek world as Athens and Delos, so much so that there were Greek comedies in which the central figure was the Carthaginian trader.