Partition of Ireland
The partition of Ireland () divided the island of Ireland into two distinct jurisdictions, Northern Ireland and Southern Ireland. It took place on 3 May 1921 under the Government of Ireland Act 1920. Today the former is still known as Northern Ireland and forms part of the United Kingdom, while the latter is now a sovereign state also named Ireland and sometimes called the Republic of Ireland.
Irish migration to Great Britain
Irish migration to Great Britain has occurred from the earliest recorded history to the present. There has been a continuous movement of people between the islands of Ireland and Great Britain due to their proximity. This tide has ebbed and flowed in response to politics, economics and social conditions of both places. Ireland was a feudal Lordship of the Kings of England between 1171 and 1541; a Kingdom in personal union with the Kingdom of England and Kingdom of Great Britain between 1542 and 1801; and politically united with Great Britain as the United Kingdom of Great Britain and Ireland between 1801 and 1922. Today, Ireland is divided between the independent Republic of Ireland and Northern Ireland.