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.
Military history of Ireland
Until 1922 secret societies, popular risings and guerilla warfare came in sporadic outbreaks in attempts to end the 1801 union of Ireland and Great Britain. Between 1919–1922 the War of Independence brought the negotiation of the Anglo-Irish Treaty and the majority of Ireland seceded from the United Kingdom to form an independent state, which immediately fell into a civil war between opposing republican factions. The northern portion of the country would form Northern Ireland becoming an autonomous part of the United Kingdom.