Great Britain had many names in its history, but the oldest is Albion.
The island of Great Britain is full of so much history, beyond what we may commonly think of with knights, castles and kings.
In fact, by the time it was known as Great Britain, centuries of history was already made there.
So, which of its numerous names were first? According to modern historians: Albion.
A lot of myths and legends surround Albion and its origins. Some believe that giants existed as the original inhabitants that eventually died out or were defeated. The largest one, named Goemagot, was flung from a cliff by Corineus, a British legend, warrior, and founder of Cornwall.
The there are many possible etymologies for Albion, but one with very significant evidence is that of a Proto-Indo-European root for "white." It could be a reference to the white southern shores of the island and the White Cliffs of Dover.
Quick fun fact: Albion was once suggested as a possible name of Canada during the Canadian Confederation.