In 1324, while staying in Cairo during his hajj, Mansa Musa, the ruler of the Mali Empire, told an Egyptian official whom he had befriended that he had come to rule when his predecessor led a fleet in an attempt to cross the Atlantic Ocean and never returned. This account, recorded by the Arab historian al-Umari, has attracted considerable interest and speculation as a possible instance of pre-Columbian trans-oceanic contact. The voyage is popularly attributed to a Mansa Abu Bakr II, but no such mansa ever reigned. Rather, the voyage is inferred to have been undertaken by Mansa Muhammad ibn Qu. A precise date for the suggested voyage is not known, though it is interpreted as having occurred in or shortly before 1312, the year Musa is inferred to have become mansa. No clear evidence of the fate of the voyage has been found. Musa's account Mansa Musa stayed in Cairo for three months in 1324 while en route to Mecca for the hajj. While there, he befriended an emir named Abu al-Hasan Ali ibn Amir Hajib, who was the governor of the district of Cairo Musa was staying in. Ibn Amir Hajib later recounted to the scholar al-Umari what he had learned of Mali from his conversations with Musa. In one such conversation, Ibn Amir Hajib had asked Musa how he had become king, and Musa responded: Al-Umari’s record of this conversation is the only account of this voyage, as it is not mentioned by other medieval Arab historians or West African oral tradition. Nonetheless, the possibility of such a voyage has been taken seriously by several historians. Identity of Musa's predecessor The identity of the mansa responsible for the voyage has been subject to some confusion. Al-Umari’s record of Musa’s account does not mention mansa’s name, giving no indication of his identity other than that he was Musa’s predecessor. According to the Arab historian Ibn Khaldun, writing several decades later, Musa’s predecessor as mansa was Muhammad ibn Qu. As such, several historians have attributed the voyage to Mansa Muhammad. Many sources call the mansa in question Abu Bakr II. However, the inclusion of a Mansa Abu Bakr II in the list of Malian rulers is an error that originated in a mistranslation of Ibn Khaldun’s text by the 19th-century European historian Baron de Slane. De Slane translated Ibn Khaldun as saying that the kingship passed from Muhammad to