If your great great great great great grandfather was from Ireland and none of your ancestors in other lines were Irish, then you would be said to be 1/128th Irish. But no one bothers with such small fractions.
Ireland is part of the British Isles. The Irish are, excepting the Loyalists in the north,(Ulster) are fiercely independent of the UK.
What is known as Great Britain is an island that is a neighbour of Ireland, but has no physical contact with it. What you are referring to is Northern Ireland, which is on the island of Ireland, as is the Republic of Ireland.
No. Athletes compete for either Ireland or Great Britain and Northern Ireland. There's been a longstanding dispute on whether the Northern Ireland area belongs to Britain or Ireland, but most people agree it's not a separate country, which is why it doesn't compete in the Olympics on its own.
Athletes from Northern Ireland who also hold Irish citizenship may represent Ireland at the Olympics. Otherwise, athletes from Northern Ireland are part of the team from Great Britain and Northern Ireland.
Yes. Northern Ireland normally competes as part of the British team, but lots of sports people from Northern Ireland compete with the Irish team.Yes. Northern Ireland normally competes as part of the British team, but lots of sports people from Northern Ireland compete with the Irish team.Yes. Northern Ireland normally competes as part of the British team, but lots of sports people from Northern Ireland compete with the Irish team.Yes. Northern Ireland normally competes as part of the British team, but lots of sports people from Northern Ireland compete with the Irish team.Yes. Northern Ireland normally competes as part of the British team, but lots of sports people from Northern Ireland compete with the Irish team.Yes. Northern Ireland normally competes as part of the British team, but lots of sports people from Northern Ireland compete with the Irish team.Yes. Northern Ireland normally competes as part of the British team, but lots of sports people from Northern Ireland compete with the Irish team.Yes. Northern Ireland normally competes as part of the British team, but lots of sports people from Northern Ireland compete with the Irish team.Yes. Northern Ireland normally competes as part of the British team, but lots of sports people from Northern Ireland compete with the Irish team.Yes. Northern Ireland normally competes as part of the British team, but lots of sports people from Northern Ireland compete with the Irish team.Yes. Northern Ireland normally competes as part of the British team, but lots of sports people from Northern Ireland compete with the Irish team.
No. He was born in America. Some of his great grandparents were Irish, but left Ireland during the 19th century. Patrick Kennedy left Ireland in 1848. Thomas Fitzgerald left Ireland in 1854. Both settled in America and married Irish women there, and from then on their family is American. It is from those two of his great grandfathers that the "Fitzgerald Kennedy" part of JFK's name comes from.
Ireland and Britain joined to become the UK in 1801. 26 counties of Ireland left the union in 1921 and became the Irish Free State (later the Irish Republic) and six Irish counties remained in the union as Northern Ireland.
Irish nationalism is only within the province of Ulster in Northern Ireland (part of the UK). A minority of the population want to leave the UK and become part of the Republic of Ireland.
An Irish person is someone born in Ireland - or a person born in another country who becomes a naturalized Irish citizen. The same rules apply to people born in Scotland or England (or naturalized). English, Scottish and Irish (Northern Ireland, not the Republic of Ireland which is in the southern part of Ireland) people are British since the three countries (plus Wales) make up the United Kingdom of Great Britain and Northern Ireland.
The "Black Irish" are the remnants of the original Iberian settlers of NW Europe over 10,000 years ago. They are found in every part of Ireland.
Northern Ireland has never been part of Great Britain. Great Britain is an island consisting of Wales, England and Scotland. Northern Ireland is on the island of Ireland which is a completely separate island. Northern Ireland, along with England, Scotland and Wales, are together known as the United Kingdom, which is probably what you are referring to. So Northern Ireland is part of the United Kingdom, but not part of Great Britain.
In 1801, Ireland became part of 'The United Kingdom of Great Britain and Ireland'.