Enigmatic "ivory rings" found in dozens of Anglo-Saxon burials in England have long baffled archaeologists, who weren't sure of the rings' origin and which animal they came from — elephants, walruses or mammoths. But now, scientific techniques have revealed that these rings likely came from African elephants living about 4,000 miles (6,400 kilometers) away, a new study finds.
The finding indicates a trading network brought the objects from eastern Africa and across post-Roman Europe to England — perhaps one of the longest trade route distances known from that time.
"It's really a long way," study co-author Hugh Willmott, an archaeologist at the University of Sheffield in the U.K. told Live Science. "It's crossing the Mediterranean world, and then the Alps, and then probably going via the Rhineland… so it's crossing multiple cultures."
The researchers analyzed one of seven so-called "bag rings" found in graves at an early Anglo-Saxon cemetery, dated to between the late fifth and early sixth centuries A.D., near the village of Scremby, about 65 miles (110 km) east of Sheffield.
After analyzing the ivory's collagen protein, the team found that the ring was made from the tusk of an African elephant (genus Loxodonta) and radiocarbon analysis revealed the pachyderm lived around the fifth century A.D. The researchers published their findings in the June issue of the Journal of Archaeological Science: Reports.
"Bag rings" have puzzled archaeologists for more than 200 years. Hundreds have been found at Anglo-Saxon burial sites in England, while a few have been found in other parts of northwestern Europe.
The rings measure between 4 and 6 inches (10 and 15 centimeters) across and they've been found only in the graves of wealthy Anglo-Saxon women. Much too large to fit a finger, they were once thought to be ornaments for the upper arm. But archaeologists now think the rings were tied around the waist and held bags that functioned as pockets, holding whatever small objects the women had to hand.
"We often find [the bags] contained objects, and they tend to be quite random," Willmott said. "Broken copper, Roman coins, things like that."
Their discovery only in wealthy graves may indicate status: "They may have been associated with women who had a special place in society," he said.
The researchers also measured the ivory's ratio of strontium isotopes (forms of the element with different neutron counts). These ratios indicate the geology of a region. The results showed that the elephant grew up in an area with geologically young volcanic rocks — probably the Rift Valley region of East Africa, Willmott said.
The lack of finds of ivory workings in Anglo-Saxon England suggests the rings were crafted in Africa — probably in Aksum, a center for ivory working at that time — and then traded until they reached England, he said. It's possible that the few bag rings found in continental Europe may be evidence of that trade.
Finds show the ivory rings were popular among Anglo-Saxons for at least 100 years. "So we're talking about a sustained trade," Willmott said. But their use seems to have ended in the seventh century, possibly because the established trade route had been disturbed.
Apart from this new evidence for importing African ivory, the Anglo-Saxons are known to have imported glassware from France, amber beads from the Baltic, amethyst beads from the eastern Mediterranean and cowrie shells from the Red Sea or India. But there are no records of the trading networks that supplied these items.
Ken Dark, an archaeologist and historian at King's College London, wasn't involved in the latest study but researches long-distance trade in Europe in the first millennium.
"This study may add to the growing body of evidence suggesting that trading networks of the fifth- to seventh- centuries were far more extensive and complex than often previously supposed," he told Live Science.
Rowan English, an archaeologist at the Centre for Urban Network Evolutions at Aarhus University in Denmark who also wasn't involved, said experts had long suspected that the bag rings were made from imported elephant ivory, and the new study was "final confirmation."
But he cautioned that other bag rings may have come from elsewhere: "My own work has recorded over 700 of these rings in cemeteries in early medieval England... more contextual and scientific work needs to be done."
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Tom Metcalfe is a freelance journalist and regular Live Science contributor who is based in London in the United Kingdom. Tom writes mainly about science, space, archaeology, the Earth and the oceans. He has also written for the BBC, NBC News, National Geographic, Scientific American, Air & Space, and many others.