A recently identified portrait of William Shakespeare, if genuine, would be the only true likeness we have of The Bard. The popular face of Shakespeare that we know was taken from a woodcut by Martin Droeshout that was published after the playwright's death. The newly-identified portrait was painted around 1610, when Shakespeare was 46 years old. The painting has been in the hands of the Cobbe family for centuries. Current owner Alec Cobbe saw another portrait that supposedly depicted Shakespeare and saw a resemblance. He then asked Stanley Wells of Birmingham University to help authenticate it.
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The two men arranged to have the Cobbe painting subjected to a battery of scientific tests — tree-ring-dating to determine the age of the wood panel, X-ray examination at the Hamilton-Kerr Institute at Cambridge University and infrared reflectography. The tests produced convincing evidence that the panel dated from around 1610 and was the source for the Folger painting, among others. Wells is now sure of it. "I don't think anyone who sees [the Cobbe painting] would doubt this is the original," he says. "It's a much livelier painting, a much more alert face, a more intelligent and sympathetic face."
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Tree ring dating would reveal the age of the tree at the time the tree was cut down to make the panel. Or not. It would not reveal how long ago that happened. Carbon dating would. And tree ring comparison with known samples from the same species during the same period from the same specific area could might possibly sort of sometimes be helpful.
http://ezinearticles.com/?Who-Was-the-Real-William-Shakespeare?&id=843099
http://en.wikipedia.org/wiki/File:Edward-de-Vere-1575.jpg