Madagan and Halawani Arab merchants, whose identity and roots are unclear. According to R. F. Morton, a critical assessment of the Book of the Zanj indicates that much of the document consists of deliberate falsifications by its author Fathili bin Omari, which were intended to invalidate the established oral traditions of local Bantu groups. The Kitab'''s ascription of Arabian origins for the founders of Malindi and other settlements on the Swahili coast is also contradicted by recorded 19th-century clan and town traditions, which instead emphasize that these early Shirazi settlers were of Persian ancestral heritage. The vast majority of modern scholars agree that there is little to no evidence of substantive Asian migration to East Africa in the medieval period. Swahili elites, many of whom had extensive trade connections with Arabia, Persia, and India fashioned themselves as a quintessential Muslim aristocracy. This demanded fictive or real genealogies that linked them back to early Muslims in Arabia or Persia, something seen in many parts of the Islamic World. It was also common for Arab, Persian, and Indian traders to "winter" on the coast for up to six months as the monsoon winds shifted. They would often marry the daughters of Swahili traders, passing on their genealogy through Islam's patrilineal descent system. The archaeological record firmly refutes any supposition of mass migrations or colonization but evidences extensive trade relations with Persia. Trade links with the Persian Gulf were especially prominent from the 10th to 14th centuries, which prompted the development of local mythologies of Persian or Shirazi origin. According to Abdulaziz Lodhi, the Iranians and Arabs called the Swahili coast Zangistan or Zangibar, which literally means "the Black Coast", and the Muslim immigrants from South Asia (modern Pakistan and India) to southern Arabian lands such as Oman and Yemen identified themselves as a Shirazi. The Muslim Shirazi settlements on the Swahili coast maintained a close relationship with those on islands such as Comoros, through marriage and mercantile networks. According to Tor Sellström, the Comorian population profile has a large proportion of Arab and African heritage, particularly on Grande Comore and Anjouan and these were under Shirazi sultanates. The contact of Shirazi people with colonial Europeans started with the arrival in Kilwa sultanate of Vasco da Gama, the Portuguese explorer, in 1498. A few years later, the Portuguese and Shirazi people entered into disputes regarding trading routes and rights particularly about gold, a