Rutherford spotted the portrait miniature during the spring but was not able to see it in person due to lockdown restrictions.
Rather than the described Sir Walter Raleigh, Rutherford knew it was of the unpopular French king thanks to research she had completed on the period that featured in the National Portrait Gallery’s 2019 show Elizabethan Treasures: Miniatures by Hilliard and Oliver.
The identity of the artist – court artist Jean Decourt (c.1530-85) – was confirmed when Philip Mould’s team bought the item and a conservator opened the painting’s frame and found the signature, ‘Decourt’ along with the date ‘1578’, on the reverse.
Unusually, despite Decourt’s high profile and status at the time, no signed portrait had been unequivocally ascribed to him.
Rutherford said: “When I spotted this at auction I knew it was of Henry III and I knew it was of that period, but I didn’t know who it was by. There are only 10 miniatures of Henri III in existence and although Jean Decourt was a central figure and artist in the Royal courts of his day no signed portraits have been unequivocally ascribed to him.”
Rutherford added: “This was that special fusion of a rare artist and a rare subject. It is one of the most exciting discoveries the gallery has made and a highlight of my career as a specialist.”
Philip Mould said: “This work is a hugely significant unpublished image of a misunderstood King, and confirmation of Jean Decourt’s immense talent. It would be wonderful if it could ‘come home’ to Paris. We have therefore given the Louvre the first opportunity to purchase it.”
A price was not given but the most recent example of a Decourt selling at auction was a small oil painting in 2016 at Christie’s which sold for a premium-inclusive £785,000.
There are very few existing depictions of Henry III partly due to his unpopularity during and after his reign. He was unpopular for many reasons including his taste for flamboyant dress, his penchant for having young men surrounding him at court and failing to produce an heir.
Although he improved the royal finances, it was also through practices such as selling offices and his lack of support in the war against the Protestants that led to the people in Paris turning against him. This led to an uprising in the capital in 1588.
He later had political rivals the Guise brothers murdered which led to his assassination by a Catholic fanatic in August 1589.