In Greek mythology, Atlas (; , Átlas) is a Titan condemned to hold up the heavens or sky for eternity after the Titanomachy. Atlas also plays a role in the myths of two of the greatest Greek heroes: Heracles (Hercules in Roman mythology) and Perseus. According to the ancient Greek poet Hesiod, Atlas stood at the ends of the earth in extreme west. Later, he became commonly identified with the Atlas Mountains in northwest Africa and was said to be the first King of Mauretania (modern-day Morocco, not to be confused with the modern-day country of Mauritania). Atlas was said to have been skilled in philosophy, mathematics, and astronomy. In antiquity, he was credited with inventing the first celestial sphere. In some texts, he is even credited with the invention of astronomy itself. Atlas was the son of the Titan Iapetus and the Oceanid Asia or Clymene. He was a brother of Epimetheus and Prometheus. He had many children, mostly daughters, the Hesperides, the Hyades, the Pleiades, and the nymph Calypso who lived on the island Ogygia. The term Atlas has been used to describe a collection of maps since the 16th century when Flemish geographer Gerardus Mercator published his work in honour of the mythological Titan. The "Atlantic Ocean" is derived from "Sea of Atlas". The name of Atlantis mentioned in Plato's Timaeus' dialogue derives from "Atlantis nesos" (), literally meaning "Atlas's Island". Etymology The etymology of the name Atlas is uncertain. Virgil took pleasure in translating etymologies of Greek names by combining them with adjectives that explained them: for Atlas his adjective is durus, "hard, enduring", which suggested to George Doig that Virgil was aware of the Greek τλῆναι "to endure"; Doig offers the further possibility that Virgil was aware of Strabo's remark that the native North African name for this mountain was Douris. Since the Atlas mountains rise in the region inhabited by Berbers, it has been suggested that the name might be taken from one of the Berber languages, specifically from the word ádrār "mountain". Traditionally historical linguists etymologize the Ancient Greek word Ἄτλας (genitive: Ἄτλαντος) as comprised from copulative α- and the Proto-Indo-European root 'to uphold, support' (whence also τλῆναι), and which was later reshaped to an nt-stem. However, Robert S. P. Beekes argues that it cannot be expected that this ancient Titan carries an Indo-European name, and he suggests instead that the word is