The Comoros may have been settled as early as the 6th century; among the peoples who crossed the sea to populate the islands are Bantu-speaking peoples, Austronesian (including Malagasy), Arabs, Somalis, Portuguese, French, and Indians. Islam probably arrived during the 10th century. The Comoros islands formed, with Zanzibar, Pemba, Lamu, and the coastal towns of Kenya and Tanzania, a united and prosperous region of Swahili culture, trading in local goods which were exported to the African coast, Madagascar, the Middle East and India. In that period, political power was in the hands of local rulers. During their explorations of the Comoros region, the Portuguese made landfall on the Islands of the Moon, in 1505; "kamar" is Arabic for "moon".