At some point before AD 942, according to the Akhbār al-zamān ascribed to al-Masʿūdī, a certain Khaškhāš gathered a crew of young men from Cordoba and set sail out into the ocean. Details of their journey are sparse, but they are recorded as having returned some time later bearing rich booty from an unknown land (Arḍ Majhūlah).
The precise identification of this Khaškhāš seems to be associated with the fleet of the Umayyad polity: a man by this name was active during a time when the fearsome Vikings were raiding as far as Iberia: a Khaškhāš was named among the commanders of the Umayyad fleet combatting Norse raiders in AD 859, while the name also occurs - as Khaškhāš ibn Saʿīd ibn ʾAswad of Pechina - among a deputation of seamen in about 890.
Also active at the time of the Viking raids was one Abū Zakariyyāʾ Yaḥyā ibn Ḥakam al-Bakrī al-Jayyānī, a.k.a. al-Ghazāl ("the gazelle"), who, along with a namesake, Yaḥyā ibn Ḥabīb, was dispatched as an embassy to these raiders, who were most likely based in Ireland. They sailed from Silves in the Algarve along with a "king of the majūs" (majūs being the name given by Ibn Diḥyah al-Kalbīy, who recounts these events, to the Northmen) to the mountain Aluwiyah, given as the westernmost point of Spain, where they are struck by a storm.
They eventually refit on an island, before being summoned. At the Viking court, al-Ghazāl meets the enchanting queen of the Northmen, named as Nud, who treats the Andalusis well. Al-Ghazāl, for his part, is rather struck by her beauty and comportment, declaring in poetry his love for her.
Some time later (the precise date is unknown, but earlier than the Christian reconquest of Lisbon in AD 1147), some eight (or, according to other sources, eighty) brave souls from that city (given by Abū ʿAbd Allāh Muḥammad al-Idrīsī as Achbouna etc.) sought to invesigate the Baḥr al-Muẓlim ("Sea of Darkness"). To this end, and having gathered enough supplies to furnish a voyage of several months, they set out westwards for eleven days, whence they came upon "a sea with heavy waves, evil-smelling, ridden with reefs and with very little light."
Somewhat preturbed by these portents, the travellers turned to the south and, after a further twelve days' sailing, made landfall on an island populated by vast flocks of sheep, from which they named the place the Jazīrat al-Ghanam. Al-Idrīsī describes it as: -
an island of vast extent, which is covered by thick darkness.
The mugharrirūn discover a spring beside a wild fig tree and slaughter a number of sheep, whose flesh was so bitter that it was practically inedible.
A further twelve days' sail in a southerly direction took them to an inhabited island, whose denizens were pale-skinned, tall and glabrous, with their womenfolk exceedingly comely. These people surround the Andalusis' vessel and hold them prisoner for three days, before they are granted an audience with the Arabic-speaking interpreter of the king, to whom they relate their tale. The king, for his part, tells the sailors of an expedition mounted by his father, who sent a number of slaves into the Baḥr al-Muẓlim. They sailed across it for a month, until they reached a region of almost total darkness and returned having made no further discoveries.
Eventually, when the west wind begins to blow, the mugharrirūn are allowed to leave and, three days later, they reach the African coast at a place which comes to be known as Safi after the leader of the group cries wa asafi ("woe is me") upon reaching this land of the Berbers.
Al-Idrīsī adds another detail: near the Jazīrat al-Ghanam is to be found another island, Raqa, the home of a bird with red plumage and eagle-like talons which lives on fish and shellfish. Raqa also boasts a fruit resembling figs which is a panacea against poisons. He also reports an incident from the Book of Wonders, in which a king of France mounted an expedition to this island. The French vessel is heard from no more. Raqa is also known as the "island of birds," and islands of sheep and birds in close proximity also feature in Irish sea lore.
Additionally, the twin islands of Cherham and Cheram, named for two piratical brothers boasting expertise in sorcery, who were transformed into rocks, are associated with an island "opposite the port of Asafi," with the atmosphere being notably free from fog. The smoke rising from the island can be seen from the mainland, which prompted Ahmed b. Omar, a.k.a. Rakkam al-Aziz, to plan a voyage, which was cancelled after his death.
A late and unreliable account describes the exploits of one Ibn Farrukh in the Fortunate Isles, in AD 999: -
He visited Guanariga, who was King or Guanarteme of Gáldar, and the Guayres or Counselors, and gave them to understand, through his interpreter, that he and his companions were sent by a powerful monarch to pay tribute to the goodness, courage, and generosity of this prince, and that they had braved the dangers of a long journey to establish friendly relations with him on behalf of their sovereign. [...] [Ibn Farrukh] sailed to the west, and surveyed four islands, designating them by the names of Ningaria, rising to the clouds; Junonia, a small island located to the south and very close to the first; and the islands Aprositus and Hero, of which the last was the westernmost. Navigating then to the east of Canaria he found Capraria and next to it Pluitana, which was near the African coast.
[A]nd he followed a way until, when he reached the setting of the sun, he found it setting in a muddy spring, and he found nearby a people.
- Qur'an [16.85-86].
Far earlier than the Arab expansion into the region was the career of Alexander the Great, who is commonly identified with the Quranic figure of Ḏu'l-Qarnayn. Though Alexander's great achievements were the conquest of the Achaemenid Empire and expeditions into the Indian Subcontinent and Central Asia, stories of his military prowess were, over the years, embellished to a vast extent, which can be seen quite clearly in the writings of al-Idrīsī and others, who record his expedition through the Baḥr al-Muẓlim.
In Imami Shi'ism, the 12th imam, Muḥammad al-Mahdi, is believed to have gone into occultation in about the year AD 941. One of the speculations about his precise location comes from the Bihar al-Anwar, which contains a report by Shaykh Salih Zainuddin Ali bin Fazil Mazandarani, who reports meeting the imam and his associates in the Jazirat al-Khadhra ("Green Island") in the midst of the Bahr al-Abyadh ("White Sea"). To reach this place, Mazandarani went through Egypt to al-Andalus, where they set off for an island opposite the land of the Berbers. Other sources speak of two cities in the furthest east and west - Jablisa and Jabliqa - where the righteous Shi'a dwell in the company of the imam, while the sons of the imam are also associated with the cities of Mubaraka, Zahira, Raiqa, Safiya, Talum and Anatis.