In the 1st century AD, the Roman Empire expanded beyond the borders of continental Europe with the British Isles in its sights. After subduing the native tribes of Britain in the south, the Romans pushed as far north as they could before stopping. The new province of the empire was known as Pretannia, the Latin term applied to the province. This gave rise to the word Britannia in English as both the name for the province and the people who inhabited the region.
On the reverse of the 2021 1 oz British Platinum Britannia Coins is the image of Britannia as designed for the Gold Britannia coins by Philip Nathan. The design captures a powerful image of Britannia on the southern coast with a trident in her right hand to control the seas and her left hand resting on the Union Jack shield.
Britannias image first appeared on coinage in the region during the Roman occupation. Emperor Hadrian issued Roman currency in the British Isles with the depiction of Britannia in 119 AD. During the 17th-century reign of King Charles II, Britannias image reappeared on British coinage.
The obverse of the British Platinum Britannia Coins features the effigy of Queen Elizabeth II. This is the fifth-generation design from Jody Clark and was created for the Royal Mint of England in July 2015. It depicts the Queen in right-profile relief wearing the Royal Diadem crown.