Zambia and large parts of Malawi. The political organization of the Maravi resembled that of the Luba and is believed to have originated from there. The primary export of the Maravi was ivory, which was transported to Swahili brokers. Iron was also manufactured and exported. In the 1590s the Portuguese endeavoured to monopolize Maravi export trade. This attempt was met with outrage by the Maravi of Lundu, who unleashed their WaZimba armed force. The WaZimba sacked the Portuguese trade towns of Tete, Sena and various other towns. The Maravi are also believed to have brought the traditions that would become Nyau secret society from Upemba. The Nyau form the cosmology or indigenous religion of the people of Maravi. The Nyau society consists of ritual dance performances and masks used for the dances; this belief system spread around the region. The Maravi declined as a result of succession disputes within the confederacy, attack by the Ngoni and slave raids from the Yao. Mutapa Empire and Mfecane As Great Zimbabwe was in decline, one of its princes, Nyatsimba Mutota, broke away from the state forming a new empire called Mutapa. The title of Mwene Mutapa, meaning "Ravager of the Lands", was bestowed on him and subsequent rulers. The Mutapa Empire ruled territory between the Zambezi and Limpopo rivers, in what is now Zambia, Zimbabwe, and Mozambique, from the 14th to the 17th century. By its peak Mutapa had conquered the Dande area of the Tonga and Tavara. The Mutapa Empire predominately engaged in the Indian Ocean transcontinental trade with and via the WaSwahili. They primarily exported gold and ivory in exchange for silk and ceramics from Asia. Like their contemporaries in Maravi, Mutapa had problems with the arriving Portuguese traders. The peak of this uneasy relationship was reached when the Portuguese attempted to influence the kingdom's internal affairs by establishing markets in the kingdom and converting the population to Christianity. This action caused outrage from the Muslim WaSwahili living in the capital, and this chaos gave the Portuguese the excuse they were searching for to warrant an attack on the kingdom and try to control its gold mines and ivory routes. This attack failed when the Portuguese succumbed to disease along the Zambezi river. In the 1600s internal disputes and civil war began the decline of Mutapa. The weakened kingdom was finally conquered by the Portuguese and was eventually taken over by