Finding Raphta, East Africa’s
Forgotten by history, the ancient city of Raphta is among Africa’s most enduring archaeological mysteries. But a barnacle-encrusted wall, submerged in turbulent waters off Tanzania’s Mafia Island, may be all that remains of it
In the Periplus of the Erythraean Sea, a ship’s log authored nearly 2 000 years ago, an unknown ship captain describes an ancient city: “The very last port of trade on the coast of Azania, called Raphta, where there are great quantities of ivory and tortoiseshell,” he writes.
Raphta was also included in Claudius Ptolemy’s Geography, his epic treatise on cartography that was completed in about 150 CE. Ptolemy listed 8000 locations known to the Roman world, including Raphta, which, tantalisingly, he called a “metropolis”.
From what scholars can piece together, Raphta is believed to be the Roman world’s southernmost trading port, part of a trade route that linked the Red Sea with what was known as the Erythraean Sea, which we now know as the Indian Ocean.
But where is this ancient city today?
Researchers have been looking for Raphta for decades. The anonymous ship captain gave detailed instructions: it was, he said, about two runs (185km) beyond Menuthias, which in turn was about 300 stades (55km) from the mainland. But Menuthias is also a mystery: it could be one of two Tanzanian islands, Pemba or Zanzibar, which are about 100km apart.
The Swahili coast has been extensively excavated by archaeologists. In recent times, these efforts have been led by Felix Chami, professor of archaeology at the university of Dar es Salaam. His research has uncovered Iron Age settlements that date back two millennia, as well as trade items from the Roman and later empires.
But Raphta eluded him, as it did Neville Chittick, the doyen of East African archaeology. Chittick died in 1984 believing that all traces of Raphta may have been washed away or buried by the ocean.
City in the sea
Enter Alan Sutton, a South African diver living in Tanzania. In April 2016, he was in a helicopter that took an unusual flight path to Mafia Island, which is a little south of Zanzibar. The tide was low and from the window he spotted a large, rectangular structure.
“Geologically speaking, Mafia Island is a sand island. There are no rocks in the area. Neither are there barrier reefs and the formation appeared highly unusual,” wrote Sutton in a web post. Sutton went back to the area to investigate. It took a few tries: waves and poor visibility hampered his initial efforts. But his persistence paid off.
“What we found was far larger than expected. A series of what appear to be wide foundations ring a large area. Along the entire perimeter created by these foundations, many thousands of square and oblong blocks lie to either side. Some — as large as five square metres and 40cm thick — have fallen off the foundation and others are still leaning against it.”
Sutton measured the foundations, which formed a rectangle about 3.7km long and 1km wide. The foundations themselves varied in width between 10m and 20m.
Sutton’s conclusion: “The site is very large, certainly the size of a city, is definitely manmade and very old. There appear to be other formations partially covered by sand in the area between the outer walls.
“There is a circular structure seven metres wide off to the side of one of the walls, but we have not [seen] it ourselves. Other than the blocks and the foundations no other items were seen.”
Sutton added: “The blocks appear to be made out of a type of matrix light brown in colour which resembles sandstone. Given the sheer number of and assumed weight of the blocks, they are likely to be made of some type of cement. Some blocks also have small perfectly square holes in them as well as oblong holes near the edges. There are no sandstone deposits known in the area. The logistics of transporting the blocks to the area would have been formidable.”
A metropolis, then nothing
In the Periplus, the captain speaks of Raphta as a port, a trading place. About 100 years later, Ptolemy described it as a metropolis. This period falls within the Pax Romana, the 200-year highpoint of the Roman empire. It is documented that there was little Roman trade with the east via the Indian Ocean before 20 CE and that it flourished after this, as a market of 56-million people, onequarter of the globe, clamoured for the best of what Asia, Africa and Arabia could offer.
The Periplus mentions ivory and tortoiseshell as Raphta’s major exports, and hardly mentions slavery, but between the first and seventh centuries CE, slaves were the principal trade between Rome and sub-Saharan African, according to British historian Caitlin Green.
The area was also already experiencing the effect of colonialism. “The region is under the rule of the governor of Mapharitis since by some ancient right it is subject to the kingdom of Arabia as first constituted. The merchants of Muza hold it through a grant from the king and collect taxes from it,” the captain tells us. Mapharitis was a province in what we call Yemen today.
But for all Raphta’s riches and prominence, it disappeared from history after being mentioned by Ptolemy. By the time Ibn Battuta, the Moroccan traveller, reached this part of the African coast in 1330, the most important trading centre had moved south by 100km, to Kilwa, which was famous for its gold markets.
Ibn Battuta, and all the other explorers that followed him, said nothing about Raphta. It was a metropolis, then it was nothing. What happened to the city? What mysteries may lie off Mafia Island?
Wall of rock
Now that researchers know where to look, the strange, man-made reef that Sutton spied from his helicopter window is clearly visible on Google Earth — a faint double scar in the otherwise pristine waters of the Indian Ocean. Could this be Raphta?
“It wouldn’t surprise me if it is a Roman structure. Rhapta was in this area without a doubt,” said Chami, speaking to journalists after Sutton briefed him about his discovery.
I spoke to Chami in late December. He is optimistic that Raphta has finally been found: “Ptolemy put Raphta at eight degrees latitude, which is Mafia and the Rufiji Delta. He also mentions one of the islands of Azania as Mafiaco, which is probably Mafia. He noted that people at Raphta were known as Rafiji, which is very close to the Rufiji people today, known as Warufiji.”