King Edward I granted the town its Royal Charter – although this particular matrix is likely to be of more recent manufacture.
The seal shows a mediaeval-style ship bearing the cross of Saint George on its masthead, together with a scene of the Crucifixion on the left. On the right, St Michael the Archangel (to whom Lyme Regis parish church is dedicated) is seen trampling on a dragon. The Latin inscription reads SIGILLUM COMVNE DE LIM, meaning "Common Seal of Lyme".
The Common Seal of Lyme is featured in a new series on the History of Lyme Regis in Museum Objects on the Museum website, produced by the Museum's research team. If you follow the link, you will find a number of in-depth PDF documents you can download, including one on this subject written by Thea Hawksworth.