The medallions show men dressed in 16th Century Italian fashion
Researchers are working to uncover the mysteries of 33 wood carved medallions which would have decorated the Royal Palace at Stirling Castle.
Historic Scotland is trying to find out why the works, known as the Stirling Heads and carved between 1530 and 1544, were created and whom they depict.
The carvings are thought to feature monarchs such as James V and England's Henry VIII.
The research is part of £12m plans to refurbish Stirling's Royal Palace.
Historians are in the process of restoring the palace to how it would have looked in the 1540s and creating a new gallery where a replica set of heads will go on display.
It is not known exactly how many of the medallions, which measure up to a metre (3ft) in diameter, were originally created and the identity of all those depicted.
The palace was begun by James V in about 1538 as a home for his new French bride Mary de Guise.
Dr Sally Rush, a senior lecturer from Glasgow University's history of art department, suspects that they feature the faces of Scottish royals taken from official portraits belonging to James V and other family members.
She said: "Had you walked into the King's Presence Chamber when the ceiling was complete I think you would have seen a whole sequence of Stewart kings, from James I to V.
"It was a statement by James V to say that his dynasty went back a long way in an unbroken line and had the inalienable right to rule over Scotland.
"The presence of Henry VIII and Margaret Tudor, mother of James V, is a reminder of his claim to the English throne.
"One of the heads which was destroyed by fire, but of which we have a sketch, may have shown Henry VIII, complete with English lion, face-on in the style developed specifically for his portraits by Hans Holbein."
Researchers also believe the heads featured great historical figures and monarchs with whom James V wanted to be associated, including Julius Caesar and Charles V.
The carvings also show a number of the male and female characters in 16th Century Italian fashions.
Dr Rush said: "These are the latest looks that would be popular with the young bucks and high-born women on the continent.
"They gave out a message that James V was in touch with what was going on across the channel, as part of modern Europe.
"One very beautiful carving in particular is of a woman in the most up-to-the-minute outfit - she's right on the money for what would have been worn at the French and Italian courts.
"I suspect that a lot of Scottish courtiers would be thinking how much they wanted to keep up by getting hold of similar clothes for themselves."