I wonder then at those who have parted off and divided the world into Libya, Asia, and Europe, since the difference between these is not small; for in length Europe extends along by both, while in breadth it is clear to me that it is beyond comparison larger; for Libya furnishes proofs about itself that it is surrounded by sea, except so much of it as borders upon Asia; and this fact was shown by Necos king of the Egyptians first of all those about whom we have knowledge. He when he had ceased digging the channel which goes through from the Nile to the Arabian gulf, sent Phenicians with ships, bidding them sail and come back through the Pillars of Heracles to the Northern Sea and so to Egypt. The Phenicians therefore set forth from the Erythraian Sea and sailed through the Southern Sea; and when autumn came, they would put to shore and sow the land, wherever in Libya they might happen to be as they sailed, and then they waited for the harvest: and having reaped the corn they would sail on, so that after two years had elapsed, in the third year they turned through the Pillars of Heracles and arrived again in Egypt. And they reported a thing which I cannot believe, but another man may, namely that in sailing round Libya they had the sun on their right hand.
Thus was this country first known to be what it is, and after this it is the Carthaginians who make report of it; for as to Sataspes the son of Teaspis the Achaimenid, he did not sail round Libya, though he was sent for this very purpose, but was struck with fear by the length of the voyage and the desolate nature of the land, and so returned back and did not accomplish the task which his mother laid upon him. For this man had outraged a daughter of Zopyros the son of Megabyzos, a virgin; and then when he was about to be impaled by order of king Xerxes for this offence, the mother of Sataspes, who was a sister of Dareios, entreated for his life, saying that she would herself lay upon him a greater penalty than Xerxes; for he should be compelled (she said) to sail round Libya, until in sailing round it he came to the Arabian gulf. So then Xerxes having agreed upon these terms, Sataspes went to Egypt, and obtaining a ship and sailors from the Egyptians, he sailed to the Pillars of Heracles; and having sailed through them and turned the point of Libya which is called the promontory of Soloeis, he sailed on towards the South. Then after he had passed over much sea in many months, as there was needed ever more and more voyaging, he turned about and sailed back again to Egypt: and having come from thence into the presence of king Xerxes, he reported saying that at the furthest point which he reached he was sailing by dwarfish people, who used clothing made from the palm-tree, and who, whenever they came to land with their ship, left their towns and fled away to the mountains: and they, he said, did no injury when they entered into the towns, but took food from them only. And the cause, he said, why he had not completely sailed round Libya was that the ship could not advance any further but stuck fast. Xerxes however did not believe that he was speaking the truth, and since he had not performed the appointed task, he impaled him, inflicting upon him the penalty pronounced before. A eunuch belonging to this Sataspes ran away to Samos as soon as he heard that his master was dead, carrying with him large sums of money; and of this a man of Samos took possession, whose name I know, but I purposely pass it over without mention.
Of Asia the greater part was explored by Dareios, who desiring to know of the river Indus, which is a second river producing crocodiles of all the rivers in the world,--to know, I say, of this river where it runs out into the sea, sent with ships, besides others whom he trusted to speak the truth, Skylax also, a man of Caryanda. These starting from the city of Caspatyros and the land of Pactyïke, sailed down the river towards the East and the sunrising to the sea; and then sailing over the sea Westwards they came in the thirtieth month to that place from whence the king of the Egyptians had sent out the Phenicians of whom I spoke before, to sail round Libya. After these had made their voyage round the coast, Dareios both subdued the Indians and made use of this sea. Thus Asia also, excepting the parts of it which are towards the rising sun, has been found to be similar to Libya.
Herodotus Book 4:40-42