Following him, others were said to have ruled all of Britain, from Roman Emperor Constantine the Great, to the mythical King Arthur (whose dominions supposedly included England, Wales, Scotland, Ireland, Denmark and France).
In the 1500s, when Henry VIII became fascinated by his Arthurian heritage, such ancient ideas began to spring up again. This has ensured that the legend of King Arthur lies at the heart of the historic British Empire.
As Wales and Ireland were under English rule, only Scotland stood in the way of a new Britannia. In the 1540s, the pro-alliance James Henrisoun called on fellow Scots to “laie doune their weapons” as “Englande was the onely supreme seat of the empire of greate Briteigne.”
It was 50 years on that John Dee – chief astrologer and cartographer to Elizabeth I – also spoke of the “Brytish Empire”, but his definition included the newly acquired colonies in North America.
As a Welshman aiding a Tudor Queen of Welsh ancestry, Dee appealed to the Arthurian notion of an overseas empire.
This expansionist understanding of the phrase remained in use throughout the 1600s, though often specified as the ‘English Empire’, but in 1707, the Act of Union between England and Scotland officially created the sovereign power of Great Britain. By the mid-1700s, use of ‘British Empire’ was widespread.
This article was taken from BBC History Revealed magazine