The British Isles is a geographic term. It includes(&always has) Ireland given that Ireland is a part of the British Isles but has never been part of Great Britain (the land mass).
The United Kingdom you refer to has a fuller name - "United Kingdom of Great Britain and Ireland" (past) replaced by "United Kingdom of Great Britain and Northern Ireland) (present).
I assume you're familiar enough with history to recognise that Ireland(landmass/people/culture) was a colony of the British (with or without your pedantry)?
The United Kingdom you refer to has a fuller name - "United Kingdom of Great Britain and Ireland" (past) replaced by "United Kingdom of Great Britain and Northern Ireland) (present).
I assume you're familiar enough with history to recognise that Ireland(landmass/people/culture) was a colony of the British (with or without your pedantry)?