Thanks, Clara, correct.
What did I mean by "UK" in this context:
I meant...
a) solely the Kingdom of England (but including Wales since 1284 ;)) until 1536,
b) the Kingdom of England and Wales until 1707,
c) The Kingdom of Great Britain until 1801 and, finally, as I was talking about the period before WWI, the United Kingdom of Great Britain and Ireland (until 1922).