What: A European Renaissance portrait of Christ, wearing the crown of thorns. It came to Ethiopia some time in the 16th century and became an icon at the heart of Ethiopia’s spiritual and political life, known as The Kwer’ata Re’esu. It was taken by the British Museum’s expert on the 1868 expedition who secretly kept it for himself. After his death it was sold on and is now in the hands of an anonymous private collector. Follow its journey through an interactive map below.

Where: In private collection in Portugal

In August 1872, another Ethiopian monarch wrote another letter to Queen Victoria. This message got through. In it, Emperor Yohannes IV asked the British to return just two of the things they had taken during their Abyssinian “expedition” four years earlier. One of them was a copy of the book known as the Kebra Nagast, The Glory of Kings – Ethiopia’s national epic including the foundational account of King Solomon, the Queen of Sheba and the Ark of the Covenant. In a stunning turn of events, the British authorities quickly tracked down two copies in the British Museum and agreed to send one of them back to Ethiopia. It made its way to Kiddus Raguel Church, in the hills above the modern-day capital Addis Ababa.

The second thing Yohannes wanted was a painting, an icon. It was ‘a picture called Qurata Rezoo, which is a picture of Our Lord and Saviour, Jesus Christ … it is surrounded with gold, and in the midst with colours,’ read the English translation of the emperor’s letter. The museum looked through its collection again, but this time came up with nothing. Queen Victoria wrote back promptly and politely to Emperor Yohannes. ‘Of the picture we can discover no trace whatsoever, and we do not think it can have been brought to England. We regret that we are therefore unable to assist you in its restoration.’

Thirty-three years later, in August 1905, a short article appeared in the back pages of the Burlington Magazine for Connoisseurs. It was headlined ‘A Flemish Picture from Abyssinia’ and included a black-and-white reproduction of the image. It described the portrait of Christ wearing his crown of thorns, painted onto an oak panel, the background and robe a deep, cool blue surrounded by an ancient frame of gilded wood, the whole thing bound in frayed crimson silk. It had been found, the magazine wrote, hanging over the bed of Tewodros after the battle of Maqdala. And it had been brought back to Britain … by Richard Rivington Holmes, the librarian the British Museum had sent on the expedition to pick up treasures for its collection.

Holmes, it turned out, had done a bit of collecting of his own on Maqdala. He brought the painting back to Britain and kept it for himself in his home in Windsor. He showed it to a visiting Belgian scholar in the 1890s, but waited more than thirty years after the battle – when the Abyssinian Expedition had all but faded from memory – before giving in to the collector’s urge to show off this treasure to the public. ‘The picture itself is hardly less interesting than its history,’ the Burlington article said in a classic understatement.

No definite details remain of who created the portrait, or where or when. Some experts suggest it is the work of a Renaissance master in Portugal or Flanders in the early 1500s, others that a Jesuit missionary painted it in Ethiopia as he tried and failed to convert its Orthodox Christian population. What there is of its story has been pieced together by historians and journalists, chief among them Richard Pankhurst and the Art Newspaper’s Martin Bailey. The first record of its existence in Ethiopia appears in the sixteenth-century imperial chronicles. They call it the Kwer’ata Re’esu – ‘the striking of His head’, a reference to the scourging of Christ before his crucifixion. And it soon outstripped its original purpose. The icon became a spiritual, imperial, national standard, carried at the head of marching armies. Subjects swore imperial oaths on the painting. Tewodros picked it up in one of his raids, possibly on Gondar, and took it back to his fortress at Maqdala.

After Holmes’s death in 1911, his widow sold it via Christie’s to a certain M. Reid of Wimbledon for £420. By 1950, it was back for sale again and, this time, the Ethiopian Embassy in London raced to raise the funds to try and buy it, in a precursor of the restitution campaigns that would build into the twenty-first century. But the embassy was too late and the painting went to a mysterious buyer known only as ‘Grey’ for £315. Richard Pankhurst established that ‘Grey’ was acting for Portuguese art expert Luiz Reis Santos, who had a patriotic interest in the painting – he once wrote an article claiming it for the Portuguese tradition over the Flemish.

Reis Santos went to New York to work at the University of Columbia and the icon passed to his wife there after his death in 1967. Decades later, in 1998, Martin Bailey reported he had found it again in a Portuguese bank vault. The picture was still wrapped in a 20 April 1950 issue of the London Evening News and was the property of a private collector who had requested anonymity.

To bring the story right up to date, the Portuguese government, presumably at the owner’s request, has since included the painting in its register of art ‘in the public interest’. It remains in the private collection. But the government also said in a decree that it could no longer be moved out of the country without the specific authorisation of the Portuguese Ministry of Culture.

A lost renaissance masterpiece claimed by both the Flemish and the Portuguese schools of painting, used as a royal standard for centuries in Ethiopia, stolen by the British Museum’s official representative on a punitive invasion then spirited away across US and European borders through a series of international auctions. Now it has resurfaced one more time, this time under the protection of the Portuguese government, setting the scene for a cross-cultural restitution battle that could put the battle for the ‘Elgin Marbles’ to shame.