Britannia silver

Britannia silver is an alloy of silver containing 11 ounces and 10 pennyweight silver in the pound troy, equivalent to 95.83% by weight silver, the balance being usually copper.
This standard was introduced in England by Act of Parliament in 1697 to replace sterling silver (92.5% silver) as the obligatory standard for items of "wrought plate". The lion passant gardant hallmark denoting sterling was replaced with "the figure of a woman commonly called Britannia", and the leopard's head mark of the Worshipful Company of Goldsmiths replaced with a "lion's head erased".