Britannia coins are British bullion coins issued by the Royal Mint in gold since 1987 and in silver since 1997.
The original Britannia silver coins contain one troy ounce (1 oz) of silver and have a face value of £2. Silver Britannias are also issued in fractional sizes of one-half, one-quarter, one-tenth, 1/20th and 1/40th of a troy ounce and with face values of £1, 50p, 20p, 10p and 5p respectively (that is, the tenth-ounce silver piece is officially denominated as 20 pence). There is also a five-ounce coin of face value £10.
Britannia as a symbol has been depicted on British coinage for centuries. The bullion series called Britannia has been issued in gold since 1987 and in silver since 1997; it has a "definitive" depiction - used on bullion coins (Brilliant Uncirculated grade), as well as one-year designs like this one - used on proofs made for collectors. In 2018, the artist David Lawrence decided to show her portrait in a classic design, wearing an ancient helmet.
The Royal Mint says:
"A Roman construct, Britannia came to personify this province at the very edge of empire. A female warrior who embodies our sense of self, she encapsulates the characteristics that define us as a nation. Throughout history, Britannia has been a muse for some of Britain’s most talented artists, each one offering their own interpretation of our most recognisable national symbol. For 2018, designer David Lawrence, whose designs include contributions to our five-year series commemorating the centenary of the First World War, restores Britannia to a more classical feel, lending her an added weight of gravitas."
This tenth-ounce silver proof coin was issued in sets only, not individually.
The obverse of the coin depicts the crowned old head of Queen Elizabeth II facing right, wearing the Royal Diamond Diadem crown worn for her Coronation (her effigy known as the "Fifth Portrait").
In small letters below the head, the artist's initials J.C (for Jody Clark).
Running continuously around the effigy is the monarch's legend: ELIZABETH II · D · G · REG · F · D · 20 PENCE ·. Translated from Latin: Elizabeth the Second, by the Grace of God, Queen, Defender of the Faith, followed by the value and denomination in English.
The reverse shows the portrait of Britannia, the female personification of Great Britain, facing right. She is wearing a crested Corinthian helmet decorated with a garland of the floral symbols of the constituent countries of the United Kingdom: the rose of England, the thistle of Scotland, the shamrock of Ireland and the daffodil of Wales.
Around, the inscription BRITANNIA 1/10oz FINE SILVER 999. Below, the date of issue 2018.
The artist's initials DL, for David Lawrence, are in the right field above the figure's shoulder.