Archaeological mysteries of Australia: How did a 12th century African coin reach Arnhem Land?
Few places in Australia feel as remote as the Wessel Islands, Northern Territory, which arch out into the Arafura Sea from the north-east of Arnhem Land. Long uninhabited, the islands are a pristine wilderness of great beauty.
However, a number of archaeological findings have suggested that the Wessel Islands are not as isolated as they seem. In 1944, the RAAF serviceman Morry Isenberg found nine coins on the beach on Marchinbar Island. Investigations revealed that they were 900 -year-old coins from Kilwa Kisiwani, a powerful medieval African sultanate located on an island off the coast of Tanzania, making them by far the oldest foreign artefact ever found in Australia.
But how did the coins get here? A number of theories have been raised. Kilwa coins have only been found twice outside Tanzania, once in Zimbabwe and once in Oman. Perhaps Kilwa sailors made the trip of more than 8000 km, only to shipwreck on the Wessel Islands. Maybe they came with an Arab ship, or a later Portuguese merchant vessel trading through the ‘Spice Islands’ after the sack of Kilwa in 1505. Or perhaps the Yolngu Aboriginal people of Arnhem Land were engaging in trade long before their well-known interactions with Macassan fishermen in the 18th century.
While the mystery of the coins remains to be solved, it is clear that the discovery reshapes the way we think about the first encounters between Australia and the outside world.
For centuries, the island of Kilwa Kisiwani (‘isle of the fish’) was home to one of the richest and most powerful empires of the Indian Ocean, at the heart of a trade network spreading from Africa through the Middle East and Asia.
The origins of Kilwa Kisiwani are shrouded in mystery. According to local oral tradition, Kilwa Kisiwani was established by the son of the Emir of Shiraz and an Abyssinian (Ethiopian) slave, Ali ibn al-Hassan, in the 10th century. The legend holds that he bought it from a local king in exchange for enough cloth to encircle the island. When the king changed his mind, it was too late, as Ali had already destroyed the bride that connected Kilwa to the mainland, claiming it for himself. Other legends claim that Ali married the local king’s daughter, giving his claim legitimacy; while other sources suggest an Arabic origin for the newcomers, likely Yemen. Later historians have suggested that these legends are metaphors for the Islamisation of the Swahili people of the area and of the transition from hunting and gathering to trade.
Either way, Kilwa Kisiwani rapidly became a thriving and wealthy seaport. The island had a safe harbour for ships and abundant fresh water. It was ideally located on the Indian Ocean trade network between India, China, Africa, and the Arab world. Kilwa became the foremost trading port from which gold and ivory, mined in Great Zimbabwe, far in the African interior, passed on its way to Fatimid Cairo. The island also exported slaves, spices, and tortoise shell. Imported goods included cloth, beads, furnishings and pottery, mostly from Asia. Chinese and Persian earthenware have been excavated by archaeologists. Kilwa also minted its own coins from the 11th to the 14th centuries.
Kilwa reached its zenith in the 14th and early 15th centuries, when it controlled Indian Ocean trade and an empire stretching along the coast from Kenya to Mozambique. Kilwa became noted for its grand architecture, as its wealthy residents built houses made of coral. The great Moroccan traveller Ibn Battuta visited in 1331 and described the city as ‘fine and substantially built’. The city was home to the Great Mosque, the largest mosque in sub-Saharan Africa (until the 16th century), and the Husuni Kubwa or ‘Queen’s House’, the largest building in pre-colonial sub-Saharan Africa.
Kilwa’s time came to an end in the early 16th century. In 1502, the Portuguese explorer Vasco da Gama forced Kilwa’s sultan to pay tribute in gold – which can still be seen in the Jerónimos Monastery, Lisbon today. The Portuguese sacked Kilwa in 1505, putting the prosperous city into a long decline. [For more information on the Portuguese Empire, check out our article about the Portuguese in Africa].
Today, the ruins of Kilwa Kisiwani are a UNESCO World Heritage Site, recognised for their ‘exceptional testimony to the expansion of Swahili coastal culture, the lslamisation of East Africa and the extraordinarily extensive and prosperous Indian Ocean trade from the medieval period up to the modern era.’
Investigating the coins:
In 1943, Maurice ‘Morry’ Isenberg was working as a RAAF radar operator on the Wessel Islands, following the Japanese bombing of Darwin. At the time, the Wessel Islands were a dangerous place, largely uncharted and subject to frequent Japanese attack. That year, the Maroubra had been sunk near the mainland, while the following year HMAS Patricia Cam was bombed by a Japanese float plane off the islands.
Taking a time off from his duties, Morry went fishing on a remote beach on Marchinbar Island, the largest in the archipelago, and stumbled across nine coins. Intrigued by his discovery, he marked the location on a map, and stored the coins in a cigarette container in his Bondi garage until he rediscovered them in 1979. Having consulted with a coin expert, he was informed that they came from Kilwa.
Morry’s son Norman recalled that, though his father believed that the coins were worth a substantial amount of money, coin collectors told him that the coins were worthless, on the grounds that the coin’s provenance (or chain of ownership) was not known. Morry donated them to the Sydney Mint Museum (now closed) in the early 1980s, and they are now held in the collection of the Powerhouse Museum.
Isenberg’s find consisted of nine coins – five from Kilwa, and four of Dutch origin. The Kilwa coins ranged in date from 1150 to 1333, while the Dutch coins date from 1690 to 1784. Dutch coins are commonly found on the coasts of Western Australia and the Northern Territory, though these were unique in being minted in Europe rather than the Dutch colony of Batavia (today’s Jakarta).
In 2013, Australian Geographic sponsored an expedition to trace the coins. The expedition was led by Mike Owen, a Darwin-based heritage consultant and Dr Ian McIntosh, an Australian anthropologist based at Indiana University in the US, with the help of the ‘Past Masters’ a team of five archaeologists and heritage experts. Incredibly, this was the first attempt to investigate the coin’s provenance: McIntosh had wanted to launch an expedition for almost twenty-five years, but could not attract funding. Working closely with the local Yolngu people, they excavated the island for artefacts that might provide clues to the origins of the coins.
In the end, the trip did not firmly establish the provenance of the coins. It remains unclear whether the Kilwa and Dutch coins came together, or simply ended up at the same place. Nonetheless, the team did make a number of interesting findings. Tracing Isenberg’s map, they ascertained that the coins were found on a crocodile-infested creek. Most likely they were flotsam washed up from a shipwreck, rather than part of an Aboriginal settlement. Near the site, the team found wooden and metal objects, including rifle cartridges, bullets, ammunition cases, an iron chisel, corroded axeheads, a bronze screw, and a polished stone axe head. They also found a piece of timber believed to be deck bracing for an old sailing ship, supporting the shipwreck theory.
The trip also looked at rock art on the Wessels for clues. Like the incredible rock art of Kakadu and Arnhem Land, rock art here records encounters with Macassan fishermen and white settlers. Art on the Wessels depicts white men with hats, trousers and guns, and many ships of different sizes, including a pearling lugger. One artwork depicts a steamship with a rotating propeller – the only one found in cave art so far. The ship appears as if it could be on the rocks with its back broken, supporting the shipwreck theory.
Yolngu oral histories provide evidence of European contact, describing white men emerging from the sea, dressed in ‘mirror’ (likely armour) and beating stones to make metal on the beach. They claim that the Yolngu and white men worked together to create knives. Traditions also speak of a hidden cave in the long-abandoned Wessel Islands full of boundless treasure, doubloons and ancient weaponry.
Where did the coins come from?
A number of theories have been offered for the provenance of the coins. Most obviously, they may indicate direct contact between Kilwa and Arnhem Land. This is not totally implausible: there was trade between Kilwa and China, and seafarers may have been blown off course and shipwrecked, or escaped from pirates into the remote southern seas. In 1550, the Portuguese writer Tome Pires wrote of the Port of Malacca (in contemporary Malaysia) having resident merchants from as far afield as Kilwa and Cairo.
Another possibility is that the coins may have come as part of a medieval Arab trading route, linking Zimbabwe, Kilwa, Arabia, Persia, India and islands in the Indonesian archipelago, including Banda and Ambon. Spices from these Indonesian islands have been found in 3500-year-old burial pits in Syria and Egypt, while the wreck of an Arab trading vessel was found off Sumatra in 1998, indicating the scope of medieval trade.
The most likely theory is that the coins came from a Portuguese ship, travelling through the area in the early 16th century, loaded with Kilwa coins in the aftermath of the 1505 sack. The Portuguese are known to have reached Timor in 1514/1515, so it is quite plausible that they made the three-day journey east to the Wessel Islands. The reference to ‘mirror’ or armour is suggestive of Early Modern visitors, rather than traders at a later date, most likely the Portuguese.
A more surprising piece of evidence points towards a French connection. One of the rock paintings has been linked to a French vessel, due to its unique rigging. Though the French were present in the Indonesian archipelago in the Early Modern Era, the area was dominated by Portuguese and Dutch traders.
Yet another suggestion is that they were used as trade trinkets by Macassan sailors in their much later (18th-19th century) period of trade with Arnhem Land. Vintage Kilwa and Dutch coins may have been in circulation in Makassar, and used as gifts in developing relationships with the Yolngu. Dutch coins, used for this purpose, have been found in Arnhem Land. However, as the Wessels are not known for trepang (the sea cucumber sought by the Macassans), this theory is less likely, though the island may have provided a place of safe harbour for sailors on the journey.
Dr. Ian McIntosh has suggested that the coins may be connected to a figure known as Buthimang to the Yolngu people (likely a translation of the Javanese name Budiman). Buthimang was an Indonesian fisherman who became an integral part of the Yolngu community, adopting local cultural practices. However, as smallpox – introduced by Macassan sailors – spread through the community, Buthimang’s loyalty came into question. He was murdered by one man, and dumped at sea, spreading division between the local community and grieving many Yolngu.
Oral tradition nonetheless associates Buthimang with the creek where Isenberg found the coin. McIntosh suggests that the coins were given as gifts by Macassan sailors in the late 18th century; and then given back to Buthimang by the Yolngu. The Yolngu likely regarded the coins as worthless to themselves, as they did not have practical value, but assumed – since they had been used as gifts – that they were of value to the Macassans, and hence gave them to Buthimang.
Since the first expedition of the Past Masters, a number of interesting finds have been made on the Wessel Islands. In 2014, the Past Masters discovered a Chinese coin, minted during the reign of Emperor Qianlong (1735-1795 AD). The coin was found within the vicinity of a known Macassan site, meaning that it most likely came with the Indonesian traders – though the possibility of direct trade with China has not been ruled out completely. Trepang was harvested primarily for a Chinese market, who saw the sea cucumber as a rare delicacy with aphrodisiac qualities.
In 2018, the Past Masters archaeologist Mike Hermes found another coin on Elcho Island, also in the Wessel Island group. Though the surface was eroded, Hermes believes that the coin may also be from Kilwa. The coin is the same size and weight – and has the same pattern on the edge – as the Kilwa coins discovered by Isenberg. The coin has been sent to Canberra for further investigation, including testing of the copper content to see if it measures up to the Kilwa coins.
The team has also become involved in other archaeological mysteries found along the Northern Territory coast. In February 2018, Dion and Jess McLean dug up a coin near Buffalo Creek, an outer suburb of Darwin. The small copper coin bears what looks like Arabic script, suggesting that it might be a 500-year-old Iranian coin, or, thanks to a small puncture on the side, a trinket from a belly dancer’s belt.
Though none of the findings have been conclusive, the archaeological mysteries posed by these coins have the power to cast Australian history in new light. In the 1960s, the historian Geoffrey Blainey diagnosed Australia as defined by the ‘tyranny of distance’, a theme that has defined Australia’s conception of self ever since. But as these coins indicate, Australia may never have been so distant after all.