Among the objects gathered into Waterford's Medieval Museum sits a stone armorial plaque whose precise origins nobody can say with confidence. It carries the Royal Arms in a form that would have been widely recognised across medieval and early modern Ireland: a shield quartered with three fleurs-de-lis and three lions passant, the combined emblems of the English crown's claim over both England and France. What makes the plaque quietly puzzling is that no one recorded where it was found, leaving its original setting as a matter of educated guesswork rather than established fact.

The most plausible suggestion, noted by the historian Charles Smith in his 1746 history of the town and county of Waterford, is that this plaque once hung above St John's Gate, one of the medieval gates that controlled entry into the walled city. City gates were a natural place for a public display of royal authority, and carved arms positioned above an archway would have made a clear statement to anyone passing through about whose jurisdiction they were entering. Whether the plaque was removed during later demolition work or came to light in some other way, the chain of custody between the gate and the museum shelf has been lost entirely.

The museum itself occupies a medieval undercroft, a vaulted underground or semi-underground chamber of the kind that once served as storage beneath grander buildings above, and the setting lends the plaque a fitting context even if it is not its original one. Visitors to the Medieval Museum in Waterford city can see the plaque there alongside other material from the city's medieval period.