Experts believe they have uncovered sufficient evidence to suggest that a Tudor-era painting could be the only known portrait of Lady Jane Grey created during her lifetime.

Known as the "Nine Days' Queen," Jane briefly reigned in an unsuccessful Protestant attempt to prevent her Catholic cousin, Mary I, from ascending the throne in 1553.

Executed at just 17 years old, if this portrait is indeed of her, it appears to have been altered over the centuries to depict her as a "subdued, Protestant" martyr. The painting is currently on loan to Wrest Park in Silsoe, Bedfordshire, where it was previously housed.

"While we cannot confirm with absolute certainty that this is Lady Jane Grey, our findings make a strong case," said Rachel Turnbull of English Heritage.

English Heritage collaborated with the Courtauld Institute of Art and dendrochronologist Ian Tyers, uncovering "evidence of what may have once been a more elaborate costume," Turnbull explained.

"It is possible that we are seeing the remnants of a once more regal portrait of Lady Jane Grey, later altered to reflect a subdued, Protestant martyr after her death," she added.

Who Was Lady Jane Grey?

• Born around 1537 at Bradgate Park, Leicestershire, she was Henry VIII’s great-niece.

• Coming from a high-status family, she received an education comparable to the king’s daughters, studying Greek, Latin, Hebrew, French, and Italian.

• Protestant King Edward VI (1547–1553) intended for her to succeed him instead of his Catholic sister, Mary.

• She was proclaimed queen on July 10, 1553, by her father-in-law, the Duke of Northumberland, but her reign lasted only until July 19.

• Following a Protestant uprising against Mary I in 1554, she was executed at the Tower of London.

• All known portraits of Lady Jane Grey were painted posthumously, the most famous being The Execution of Lady Jane Grey (1822) by Paul Delaroche, depicting her blindfolded before the executioner's block.