A small engraving of a good-looking mustachioed man with a wreath of laurel in his curly hair is the subject of an extraordinary claim: that it is the only “true” portrait of William Shakespeare made in his lifetime.

That claim comes from botanist and historian Mark Griffiths, who will publish his findings in Country Life magazine. According to the magazine, the small black-and-white visage is the “first and only known demonstrably authentic portrait” of William Shakespeare made while the Bard was still alive. The magazine’s editor, Mark Hedges, believes it is the “literary discovery of the century.”

Griffiths’ work is the latest in a series of discoveries that have, to varying degrees of authenticity, claimed over the years to show once and for all what Shakespeare really looked like.

While an exciting idea, the Griffiths portrait will have to remain a “whoa, if true” discovery for now.

Shortly after the portrait’s unveiling, some Shakespeare scholars were openly skeptical. Professor Michael Dobson, director of the Shakespeare Institute at the University of Birmingham, told the BBC he was “deeply unconvinced,” by the image and the information published so far.

“Country Life is certainly not the first publication to make this sort of claim,” he said.

Speaking to the Independent, Dobson said: “I can’t imagine any reason why Shakespeare would be in a botany textbook. … I don’t think very many people are going to take this seriously.”

Country Life said in a press statement Tuesday that it will release a more thorough accounting of the methodology used by Griffiths to verify the portrait on Wednesday.

In summarizing those findings, the magazine’s press release spins a Dan Brown-esque narrative of how the portrait was identified: by cracking an “ingenious Tudor code — in which rebuses, ciphers, heraldic motifs and emblematic flowers were used to identify names and social position.”

Griffiths found the portrait in a copy of “The Herball: Generall Historie of Plantes” by John Gerard, a Tudor-era botanist, surgeon and horticulturist. The “Shakespeare” portrait is one of four small engravings found on the title page of the rare book.

Title pages of the era are conventionally illustrated with mythical and historical figures, so, Griffiths said, most assumed the same was true of “Herball’s” title page. But Griffiths disagreed and said he was easily able to use “symbolic allusions” to identify the other three men on the title page as Gerard himself, Flemish botanist Rembert Dodoens and Lord Burghley, the Queen’s Lord Treasurer.

When it came to the fourth man, Griffiths said that he believes a laurel wreath on the man’s head, an ear of sweetcorn, and a “distinctive fritillary” are all references to Shakespeare’s plays. The latter two symbols were references to “Venus and Adonis” and “Titus Andronicus,” Griffiths said, while the laurel wreath was a reference to Apollo and to the classical poetry that often found its way into Shakespeare’s work.

The finishing touch for Griffiths was an “an ingenious cipher of the kind loved by the Elizabethan aristocracy” under the portrait’s name, which Griffiths says he cracked to read “William Shakespeare.”

And Griffiths believes that the portrait, while small, is hardly a caricature, but instead a true depiction of what Shakespeare looked like at the height of his health and popularity. “The Fourth Man is not cartoonish or stylised,” Griffiths said in a statement. “It may be monochrome, in fancy dress, and just 3 ½ in tall, but this is something that has been sought for centuries.”

“This is what Shakespeare looked like, drawn from life and in the prime of life,” Griffiths said.

Griffiths sought help in verifying the portrait from Edward Wilson, emeritus fellow of Worcester College, Oxford. Wilson told the BBC that he and Griffiths have taken precautions to make sure their work will stand up to scrutiny. They’ve spent five years trying to disprove the discovery with the help of other scholars, he said. “We do not think anyone is going to dispute this at all,” Wilson said.

The Guardian published a few of Griffiths’ findings later on Tuesday. “A W – for William? And Or? A few months before it was engraved, Shakespeare’s father was granted a coat of arms with a golden background. The heraldic term for gold is Or,” was one such example.

Those, too, were met with some skepticism from scholars.

There is another reason Shakespeare watchers could remain skeptical of the new portrait, for now: This is hardly the first time someone has claimed to uncover an image showing how Shakespeare really, truly looked.

One of the more credible claims comes from a posthumous engraving that adorns a 1623 First Folio of Shakespeare’s work, by a young engraver named Martin Droeshout. As the National Portrait Gallery in London points out, Droeshout was 15 when Shakespeare died in 1616. But it’s likely he based his likeness on a description of the man by Shakespeare’s friend, Ben Jonson, who later praised Droeshout’s accuracy.

It’s not definitive, but the Droeshout is one of two posthumous works generally believed to approach what Shakespeare really looked like. The other is a sculpture at Shakespeare’s tomb.

The Droeshout has been copied to varying degrees of success by a few other portraits claiming authenticity. For instance, there’s the Flower Portrait, which was originally dated as a painting from 1609, or before Shakespeare’s death. However, the widely known Flower Portrait is actually a forgery, the NPG later determined.

How? As it turns out, one of the yellow dyes used for the painting dates only from 1814.

There’s also the Cobbe portrait, otherwise known as the “dreamy hunk Shakespeare” portrait. Professor Stanley Wells, chairman of the Shakespeare Birthplace Trust, said in 2009 that he was “willing to go 90 per cent of the way to declaring my confirmation that this is the only life time portrait of Shakespeare.” The argument for the Cobbe portrait’s authenticity is interesting but also very complicated, meaning that some are still skeptical that the very different image of the Bard is also a likeness of him.

For his part, Wells was skeptical of the botany portrait:

Which prompted this nerdy joke:

The Janssen portrait, to which the Cobbe bears some resemblance, is in the Folger Shakespeare Library’s collection. The Janssen was originally a portrait based on a sitting of another, unidentified man. It was later painted over to make it more resemble Shakespeare.

Last February, a German researcher claimed that she had uncovered two more portraits of Shakespeare, called the Wörlitz portrait and the Boaden portrait, one from his youth and one from his old age. Again, the claim produced quite a lot of skepticism.

If it turns out that Griffith has uncovered an actual portrait from the life of William Shakespeare, he will have some competition on the claim that his discovery is also the only lifetime portrait of the Bard. The NPG has already said that it has considerable reason to believe the Chandos portrait in its London collection dates from 1600 to 1610 and is a representation of Shakespeare from his life.

Next week, Country Life says, the magazine will also reveal a “new play” by the Bard.