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The Partition of Ireland (1921)

Why the island of Ireland was divided into the Irish Free State and Northern Ireland.

After the Easter Rising of 1916 in Dublin and a bitter war of independence from 1919 to 1921, the British government negotiated the Anglo-Irish Treaty of 1921. It partitioned the island of Ireland: 26 counties in the south and west became the Irish Free State (since 1949 the Republic of Ireland), while six counties in the north-east, with a Protestant unionist majority, remained part of the United Kingdom as Northern Ireland.

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The Stormont Parliament was set up to give Northern Ireland a measure of self-government. The Irish Free State left the Commonwealth in 1949 and became a republic; Northern Ireland remains part of the UK. The partition still shapes politics on both sides of the border.

You may be asked the year of partition (1921), the name of the new state in the south (Irish Free State), or how many Irish counties stayed in the UK (six).

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