For centuries the Arabs sailed with the monsoon winds from Oman to trade primarily in ivory, slaves and spices. The two main islands, Unguja (normally known as Zanzibar Island) and Pemba, provided an ideal base for the Omani Arabs, being relatively small, and therefore fairly easy to defend. Indeed, in 1832, Sultan Seyyid Said, of the Busaid dynasty that had emerged in Oman, moved his Sultanate from Muscat to Zanzibar, perhaps making it easier to protect, where he and his descendants ruled for over 130 years. Most of the wealth lay in the hands of the Arab community, who were the main landowners at that time. They kept themselves to themselves, and generally did not intermarry with the Africans.   Beach view. Zanzibar, Tanzania.[/caption] This was not true of the Shirazi Persians who came from the Middle East to settle on the East African coast. The story goes that in AD 975, Abi Ben Sultan Hasan of Shiraz in Persia (now Iran) had a terrible nightmare in which a rat devoured the foundations of his house. He took this as an omen that his community was to be devastated. Others in the Shirazi court ridiculed the notion, but Sultan Hasan, his family and some followers obviously took it very seriously and they decided to migrate. They set out in seven dhows into the Indian Ocean but were caught in a huge storm and separated. Thus, landfalls were made at seven different places along the East African coast, one of which was Zanzibar, and settlements began.