10 Shillings - Elizabeth II William I

Issued to mark the 900th anniversary of the Norman Conquest, this was Guernsey's first commemorative decimal-adjacent coin — struck before the island formally decimalized in 1971. The timing was deliberate: Guernsey, as a Crown Dependency with deep Norman roots, had stronger historical claim to the occasion than Britain itself. The Duchy of Normandy connection is not merely ceremonial; Guernsey has never technically been part of the United Kingdom, and the anniversary carried genuine local weight.

KM#19 was struck at the Royal Mint, with a mintage just over 200,000 — modest by commemorative standards of the era.