Irish immrama. The peoples of the Iberian peninsula, who were closest to the real Atlantic islands of the Canaries, Madeira and Azores, and whose seafarers and fishermen may have seen and even visited them, articulated their own tales. Medieval Andalusian Arabs related stories of Atlantic island encounters in the legend (told by al-Masudi) of the 9th-century navigator Khashkhash of Cordoba and the 12th-century story (told by al-Idrisi) of the eight Maghrurin (Wanderers) of Lisbon. Given the tendency of the legends of different seafarers – Greek, Norse, Irish, Arab and Iberian – to cross-fertilize and influence each other, the exact source of some legendary Atlantic islands – such as the mythical islands of Brasil and the Isle of Mam – are extremely difficult to disentangle. It is from Christian Iberia that the legend of Antillia emerged. According to the legend, in c. 714, during the Muslim conquest of Hispania, seven Christian bishops of Visigothic Hispania, led by the Bishop of Porto, embarked with their parishioners on ships and set sail westward into the Atlantic Ocean to escape the Arab conquerors. They stumbled upon an island and decided to settle there, burning their ships to permanently sever their link to their now Muslim-dominated former homeland. The bishops erected seven settlements (the "Seven Cities") on the island. In one reading (from Grazioso Benincasa), the seven cities are named Aira, Antuab, Ansalli, Ansesseli, Ansodi, Ansolli and Con. The legend, in this form, is told in various places. The principal source is an inscription on Martin Behaim's 1492 Nuremberg globe which reads (in English translation): The legend is also found inscribed in the 1507/08 map of Johannes Ruysch, which reads (in English): Ruysch's inscription is reproduced almost verbatim in the Libro of Spanish historian Pedro de Medina (1548). Medina gives the island's dimensions as 87 leagues in length and 28 in width, with "many good ports and rivers", and says it is situated on the latitude of the Straits of Gibraltar, that sailors have seen it from a distance, but disappears when they approach it. The adjustment to the 714 date and the burning of the ships is due to Ferdinand Columbus (1539), who also reports an alleged encounter with the islanders by a Portuguese ship in the time of Henry the Navigator (c. 1430s–1440s). António Galvão (1563) reports that a 1447 Portuguese ship stumbled on the island, and met its (Portuguese-speaking) inhabitants, who reported