The Rufiji River lies entirely within the African nation of Tanzania.

It is formed by the convergence of the Kilombero and Luwegu rivers. It is approximately 600 km (375 mi) long, with its source in southwestern Tanzania and its mouth on the Indian Ocean opposite Mafia Island. Its principal tributary is the Great Ruaha river. It is navigable for about 100 km (60 mi).

It is about 200 km (120 mi) south of Dar-e-Salaam. The delta contains the largest mangrove forest in the world.

It has been proposed that the site of ancient Rhapta - the southermost trading port mentioned in the 1st century CE Periplus of the Erythraean Sea, was situated near the mouth of the Rufiji River. Professor Felix Chami has uncovered impressive evidence of Roman trade with the region in the first few centuries CE.

References

• Casson, Lionel. 1989. The Periplus Maris Erythraei. (Translation by H. Frisk, 1927, with some updates and improvements). Princeton, Princeton University Press. (This is probably the most accurate translation of the Periplus into English and also includes the Greek text).
• Chami, F. A. 1999. "The Early Iron Age on Mafia island and its relationship with the mainland." Azania Vol. XXXIV 1999, pp. 1-10.
• Chami, Felix A. 2002. "The Graeco-Romans and Paanchea/Azania: sailing in the Erythraean Sea." From: Red Sea Trade and Travel. The British Museum. Sunday 6 October 2002. Organised by The Society for Arabian Studies. [[1]]
• Hill, John E. 2004. The Peoples of the West from the Weilue 魏略 by Yu Huan 魚豢: A Third Century Chinese Account Composed between 239 and 265 CE. Draft annotated English translation. See especially, Section 15 on Zesan = Azania, and notes. [2]
• Huntingford, G. W. B. 1980. Periplus of the Erythraean Sea. London: the Hakluyt Society.
• Miller, J. Innes. 1969. Chapter 8: "The Cinnamon Route". In: The Spice Trade of the Roman Empire. Oxford: University Press. ISBN 0-198142641
• Ray, Himanshu Prabha, ed. 1999. Archaeology of Seafaring: The Indian Ocean in the Ancient Period. Pragati Publications, Delhi.
• Schoff, Wilfred H. 1912. The Periplus of the Erythræan Sea. New York, Longmans, Green, and Co. Second Edition. Reprint, New Delhi, Oriental Books Reprint Corporation. 1974.