2023 Britannia Silver 2 oz Proof With OGP Box & COA RARE Only 1000 Minted! Mintage of Only 1000! Just 1,000 Britannia silver coins available in this Limited Edition Presentation. Struck in two ounces of 999 fine silver to Proof standard. The first commemorative Proof Britannia coin to feature the portrait of His Majesty King Charles III. Artist Jonathan Olliffe’s design features seahorses, inspired by royal carriages used during processions.