You were born in England on the land mass known as Great Britain which makes you a citizen of the United Kingdom you were always told England was your country of birth if not what is?

If you were born in England, you're English, if you were born in Wales you're Welsh, if you were born in Scotland you're Scottish, if you were born in Northern Ireland you're Irish. All these are part of the United Kingdom of Great Britain and Northern Ireland. The most commonly used collective term for anyone born in any of these places is "British" but you can certainly claim to be English if you were born in England.