The Periplus of the Erythraean Sea, (Indian Ocean) written in approximately AD50 (1) , describes a well established trade route, linking Arabia with Azania, as the east coast of Africa was known in the Graeco-Roman era. The principal port of trade was Mocha (or Merku and Mark'a) in present day Yemen, and the last port in Azania was Rhapta, lying some two courses (a sailing measure, possibly tacks) from the island of Menouthesias, itself 300 stadia - a measure of distance equivalent to about 50 km - from the coast. Menouthesias was "...a low island covered with trees in which are rivers...". according to the Periplus. And Rhapta lay to the south "...beside and to the east of a cape with a river..." according to a separate source, Ptolemy (2) , in his famous Geographia. The locations of both Menouthesias and Rhapta have confounded scholars since the Periplus was first translated in 1912. Some scholars argue that Zanzibar or Pemba may be the fabled Menouthesias with Rhapta somwehere between Bagamoyo and Dar es Salaam.
http://nabataea.net/mafia.html
http://nabataea.net/mafia.html