This gold Quarter Guinea coin dates from 1718, during the reign of King George I (1714-27). The coin is just 15mm in size!
On this reverse side you can see three shields representing Britain following the Act of Union in 1707 and a shield representing the Duchy of Brunswick and Luneberg, which were also ruled by George I.
At the centre of the design is the crown of Charlemagne (the first Holy Roman Emperor) and between the shields are sceptres, symbolising royal power and were commonly used on coins as far back as late Anglo-Saxon Kings.