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.
Counties of Northern Ireland
It was not until the reign of Queen Elizabeth I that Ulster would be shired into more counties, based largely on the boundaries of existing lordships. In 1584, Lord Deputy of Ireland Sir John Perrott created the following counties in what is now Northern Ireland: Armagh; Coleraine; Fermanagh; and Tyrone. Carrickfergus would retain its status as a county town until 1777 when it was merged with County Antrim.