From early times Greeks were acquainted with, or at the least aware of, their neighbours to the east and north east. Voyages to these regions— presumably for trading—are reflected in the legend of the Argonauts, in the exploits attributed to Aristeas of Proconnesus, and in the mythical wanderings of Io recounted in Aeschylus, Prometheus Bound. Her route takes in Scythians, Chalybes and Amazons to the north; next the Caucasus, Cimmerii and the Bosporus; then Asia, haunt of the fabulous Graeae, the mute hounds of Zeus, and the one-eyed Arimaspians. Thereafter she turns south to the Aethiopes and the R.Nile. In the fifth century Herodotus made extensive researches on Egypt, Scythia, the Persian empire, and India, some of them by personal observation. His only Greek predecessor was Scylax of Caryanda, who in a voyage of coastal exploration undertaken c. 510 for the Great King Darius set off from near Attock on the R.Indus and sailed as far as Arsinoe. Before Scylax, two Carthaginians, Himilco (c. 525) and Hanno (c. 500), had sailed respectively to right and left out of the Pillars of Hercules (Straits of Gibraltar). Himilco reached Brittany, but probably did not go as far as Britain. From the account in Polybius it would seem that Hanno reached Sierra Leone, or possibly even Cameroon. This is further than any other traveller before the Middle Ages, unless the report in Herodotus be accepted of a circumnavigation of Africa by a Persian named Sataspes during the reign of Xerxes (486–65). It is appropriate to mention here the March of the Ten Thousand led by Cyrus the Younger, which forms the subject of Xenophon’s Anabasis (see p. 58). His march seems to have been emulated in part by Alexander the Great, who crossed the Hellespont in 334 to begin his remarkable campaign of conquest of the Persian empire (see pp. 64–5). Alexander’s expedition included a geographer and other scientific staff, and aimed to record scientific information as well as to make conquests. In 329 he passed the ‘Caspian Gates’ and entered hitherto unexplored territory. He was in central Asia and northern India until 326. His admiral Nearchus was despatched down the R. Indus to seek a sea route back to Persia, while Alexander led his army through the burning Gedrosian desert of south Iran, finally reaching Susa in 324. The British Isles were visited c. 310 by Pytheas, a captain from Massilia, who sailed north out of the Pillars of Hercules. Though he is mentioned by Dicaearchus and Strabo, most of our information comes from Diodorus and Pliny. Besides apparently circumnavigating Britain he sailed into the North Sea, reporting a condition where sea and air merge in a kind of jelly (a thick fog plus floating ice?). His tantalising island, Ultima Thule, has been variously identified as Iceland or part of the Norwegian coast. In the late first century BC Eudoxus of Cyzicus made two voyages to India, on the second of which he was blown down the African coastline. According to Strabo, this experience prompted him to try the circumnavigation the other way. Here he was driven aground by the north east trade wind and turned back; but after reaching the Canary Islands the expedition was lost, from causes unknown. Several ancient explorers penetrated the Sahara desert. Herodotus records one journey through it by five men of the Berber tribe of the Nasamones. But this lead was hardly followed until Roman times. Then, in 19 BC, Cornelius Balbus, proconsul of Africa, explored south into the desert. In the late first century AD another proconsul, Septimius Flaccus, made a three-month march inland, while Julius Maternus at some unknown date extended the route to the Sudan. In AD 42 Suetonius Paulinus crossed the Atlas. But in general Romans were not prompted by such scientific curiosity as Greeks.
Richard J.A.Talbert, Atlas of Classical History, σ. 55.