Great Britain is the larger of the the two islands that make up the British Isles. Great Britain is the bit that contains England, Scotland and Wales. Lesser Britain is the smaller island that contains the Republic of Ireland (Eire) and Northern Island. Hence, Great Britain and Northern Ireland.
Some ancient geographers did make the distinction between the island of Britain as “Great Britain” and Ireland as “Lesser Britain”. But no-one who actually lived in Ireland, Great Britain, or any neighboring country in Europe seems actually to have called Ireland “Lesser Britain” except when quoting those old writers.
On the other hand, people in the dark ages and middle ages did call Britanny “Britain” or “Lesser Britain”, to the point where there is sometimes confusion to this very day concerning the interpretation of historic documents. In French, they are called “Bretagne” and “Granbretagne” even now.
When the United Kingdom of Great Britain was founded, “Great Britain” effectively meant “Britain as opposed to Britanny”, not “Britain as opposed to Ireland”.
For your information “Lesser” Britain ( :eek: ) is the island of Ireland which remains divided consisting of 32 counties in total. The South, or Republic, contains 26 counties and the North, or Northern Ireland, contains 6 counties.
Actually, come to think of it, rather than “Lesser Britain”, a more appropriate tag for Ireland (well, the Republic at any rate) these days would be “mini America”
Except that there is no evidence that Ireland was ever called “Lesser Britain” by anyone living within a thousand miles, whereas there is plenty of evidence that Britanny not only was, but in some languages still is.