Henry VIII and Catherine of Aragon famously parted on tricky terms, but the National Portrait Gallery announced on Thursday it was reuniting the royal couple after it discovered an image of the devoutly Catholic queen hanging in, of all places, Lambeth Palace.
The gallery said a portrait always thought to be of Catherine Parr, Henry's sixth wife who survived him, was in fact a depiction of the other Catherine – his first wife and the one his quest to divorce led to the titanic split with the Catholic church.
It has hung in a private sitting room of the official residence of the archbishop of Canterbury at least since the 19th century and probably longer.
The NPG's Charlotte Bolland called it "an exciting discovery", made when gallery staff went to Lambeth Palace to research its portrait of William Warham, the man who married Henry and Catherine as archbishop of Canterbury in 1509.
During the visit the Catherine portrait was spotted. "It was immediately apparent that it was in a very early frame, something which was a relatively rare survival from the early 16th century. It was a way of frame-making that went out of fashion. That was a kind of instant sign that it was something quite interesting."
The woman's costume also looked far more 1520s than 1540s, leading to gallery staff questioning whether it was Catherine Parr.
Lambeth Palace allowed the painting to be taken to the NPG's conservation studio where x-ray and infrared research helped lead to the conclusion that it was in fact Catherine of Aragon.
The research is part of the NPG's Making Art in Tudor Britain project, for which Bolland is curator. It has already thrown up fascinating discoveries, such as the finding that a portrait of Elizabeth I's spymaster, Sir Francis Walsingham, had been painted on a Catholic devotional image of the Madonna and Child, quite possibly mischievously.
The NPG, also with mischief, has now hung the Catherine of Aragon portrait, on loan to it for five years, next to one of Henry from the same time. And next to the unhappy couple is Anne Boleyn, the other woman who became Henry's second wife until her execution, by beheading, in 1536.
• Henry and Catherine Reunited is on display in Room 1 of the National Portrait Gallery from 25 January.
