Medieval England
The next few hundred years saw England as an
important part of expanding and dwindling empires based
in France, with the "King of England" being a subsidiary title of a succession of French-speaking Dukes of territories in what is now France. Only when English kings realised that their losses in France meant that England was now their richest and most
important possession did they accept the same "nationality" and language as their subjects in England. They used England as a source of troops to enlarge their personal holdings in France for many
years (Hundred Years'' War); in fact the English crown did not relinquish its last foothold on mainland France until Calais was lost during the reign of Mary Tudor (the Channel Islands are still crown dependencies, though not part of the UK).
The Principality of Wales, under the control of English monarchs from the Statute of Rhuddlan in 1284, became part of the Kingdom of England by the Laws in Wales Acts 1535–1542. Wales shared a legal identity with England as the joint entity originally called England and later England and Wales.