Two lion skulls found during excavations at the Tower of London originated in north-west Africa, genetic research suggests.
The big cats, which were kept by royals during medieval times, have the same genetic make-up as the north African Barbary lion, a DNA study shows.
Experts believe the animals were gifts to English monarchs in the 13th and 14th centuries.
At the time, the Barbary lion roamed across much of Africa.
The two well-preserved lion skulls were recovered during excavations of the moat at the Tower of London in 1937. They have been radiocarbon dated to AD 1280-1385 and AD 1420-1480.
Researchers at the University of Oxford extracted DNA from the skulls, and found that it matched that of the north African Barbary lion.
The Barbary Lion is a subspecies of lion that is now extinct in the wild
There are about 40 in captivity in Europe, with less than a hundred in zoos around the world
The Barbary lion formerly lived in North Africa from Morocco to Egypt
Comparison with the skulls of Asiatic and north African Barbary lions kept in museums in the UK and Europe gave further evidence of the link.
Dr Richard Sabin, Curator of Mammals at London's Natural History Museum, said the results were the first genetic evidence to clearly confirm that lions found during excavations at the Tower of London originated in north Africa.
He said: "Although we have one of the best mammal collections in the world here at the Natural History Museum, few physical remains survive of the Royal Menagerie.
"Direct animal trade between Europe and sub-Saharan Africa was not developed until the 18th Century, so our results provide new insights into the patterns of historic animal trafficking."
In historical times, the lion was found across Africa, the Middle East and India.
Dr Nobuyuki Yamaguchi of the Wildlife Conservation Unit at the University of Oxford said the growth of civilisations along the Egyptian Nile and Sinai Peninsula almost 4,000 years ago stopped gene flow, thereby isolating lion populations. The lion survived in the wild in western north Africa until about 100 years ago.
Dr Yamaguchi said: "Western north Africa was the nearest region to Europe to sustain lion populations until the early twentieth century, making it an obvious and practical source for mediaeval merchants.
"Apart from a tiny population in north-west India, lions had been practically exterminated outside sub-Saharan Africa by the turn of the 20th Century."
The Royal Menagerie was a collection of lions, leopards, bears and other exotic animals that were probably gifts to English monarchs.
It was established in the 12th and 13th Centuries by King John, in Woodstock near Oxford, and was later moved to the Tower of London. It was finally closed in 1835, on the orders of the Duke of Wellington.
The remaining animals were moved to the Zoological Society's Gardens in Regent's Park, now known as London Zoo.
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