Around the outside of the figure runs a Latin inscription — “Ottonis” — referencing the archbishop. On the back, the 600-year-old coin is decorated with von Ziegenhain’s coat of arms, the museum said.

The memorial was designed by Sir Henry Cheere and includes a bust of the archbishop with decorations of a mitre, crozier, lamps, sprays of oak leaves and acorns. The coat of arms at the base once ...