Issued for the 1969 Investiture of the Prince of Wales at Caernarfon Castle, this 9d commemorative features a striking Celtic cross monument with intricate knotwork symbolizing Welsh heritage. The warm brown background contrasts elegantly with the detailed stone cross engraving. The Queen’s Machin silhouette and bilingual inscription “Twysog Cymru” emphasize its royal and cultural significance. A popular thematic piece for Wales, royalty, and Celtic art collections. Clean examples with sharp perforations are especially desirable for display and stock books.