She was Queen of England for nine days in 1553, but historians have had to rely on contemporary descriptions of Lady Jane Grey’s appearance as no portrait was thought to have survived from her lifetime.

Now a miniature measuring less than 2in (5cm) in diameter has been identified as a portrait of England’s briefest monarch. It had languished in an American collection, its subject described as “unknown woman”.

After 12 months of research, David Starkey, the Tudor specialist, believes that it is a contemporary portrait of Lady Jane Grey, the great-granddaughter of Henry VII who was deposed and beheaded by Mary I. “Jane need not remain one of history’s invisible women,” Dr Starkey said.

He believes that it bears the hand of Lavinia Teerlinc, the 16th-century painter of miniatures. Dr Starkey found the portrait in a book and looked into it because portraits of women in the 1550s, the beginning of British portrait painting, are so rare. He said: “Almost all the early miniatures such as this were of royal subjects. What I noticed was the evident youth of the sitter. It would be unusual for someone to sit for a miniature unless they had very high status.”

His eye was drawn to the brooch worn by the sitter and the spray of foliage behind it. In the inventory of jewellery that Lady Jane had owned, he found a gold brooch with an agate centre that matched the one in the miniature.

In the spray of foliage, he discovered the badge of the Dudley family. John Dudley, Duke of Northumberland, was the effective ruler of England during the last days of Lady Jane’s cousin, the boy king Edward VI. Under the influence of Northumberland, whose son Guildford Dudley married Lady Jane in 1553, Edward VI willed her the Crown, but she was captured by supporters of Mary Tudor and executed in 1554.

Dr Starkey realised that the foliage included a gillyflower, a symbol for Guildford Dudley. Each of Northumberland’s sons was represented by a flower; Ambrose by a rose, Henry by honeysuckle, Robert by an acorn and Guildford by the gillyflower. Such floristry is symbolic, Dr Starkey said: “It is not a sign of green fingers but the identifiable ‘badge’ of a family of distinction.”

The miniature is inscribed ANO XVIII — the sitter’s 18th year. It was thought that Lady Jane was 16 when she was executed, but this means that she could have been older. Dr Starkey said: “We can therefore rule out the traditional date of October 1537, which was probably born out some romantic notion that Jane was the exact contemporary of her royal cousin Edward VI.”

The miniature was bought by the late collector Paul Mellon, at Sotheby’s in 1970 with another piece, for £760. It is on view until March 18, as part of the Lost Faces exhibition at Philip Mould Historical Portraits in London. features and a

A description of Lady Jane Grey, written during her reign

"She has well-made nose, the mouth flexible and the lips red. The eyebrows are arched and darker than her hair, which is nearly red."

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