The county of Corki s colloquially referred to as "The Rebel County". This name has 15th Century origins, but from the 20th century the name has been more commonly attributed to the prominent role Cork played in the Irish War of Independence (1919–1921) when it was the scene of considerable fighting. In addition, it was an anti-treaty stronghold during the Irish Civil War (1922–23). Much of what is now county Cork was once part of the Kingdom of Deas Mumhan (South Munster), anglicised as "Desmond", ruled by the MacCarthy Mór dynasty. After the Norman Invasion in the 12th century, the McCarthy clan were pushed westward into West Cork and County Kerry. Dunlough Castle, standing just north of Mizen Head, is one of the oldest castles in Ireland (A.D. 1207). The north and east of Cork were taken by the Hiberno-Norman FitzGerald dynasty, who became the Earls of Desmond. Cork City was given an English Royal Charter in 1185 and again in 1318 and for many centuries was an outpost for Old English culture. The Fitzgerald Desmond dynasty was destroyed in the Desmond Rebellions of 1569–1573 and 1579–83. Much of county Cork was devastated in the fighting, particularly in the Second Desmond Rebellion. In the aftermath, much of Cork was colonised by English settlers in the Plantation of Munster.
In 1491 Cork played a part in the English Wars of the Roses when Perkin Warbeck, a pretender to the English throne, landed in the city and tried to recruit support for a plot to overthrow Henry VII of England.The Cork people fought with Perkin because he was French and not English, they were one of the only counties in Ireland to join the fight. The mayor of Cork and several important citizens went with Warbeck to England but when the rebellion collapsed they were all captured and executed. Cork's nickname of the 'rebel city' originates in these events.
In 1601 the decisive Battle of Kinsale took place in County Cork, which was to lead to English domination of Ireland for centuries. Kinsale had been the scene of a landing of Spanish troops to help Irish rebels in the Nine Years' War (1594–1603). When this force was defeated, the rebel hopes for victory in the war were all but ended. County Cork was officially created by a division of the older County Desmond in 1606.
In the 19th century, Cork was a centre for the Fenians and for the constitutional nationalism of the Irish Parliamentary Party, from 1910 that of the All Ireland Party. The county was a hotbed of guerrilla activity during the Irish War of Independence (1919–1921). Three Cork Brigades of the Irish Republican Army operated in the county and another in the city. Prominent actions included the Kilmichael Ambush in November 1920 and the Crossbarry Ambush in March 1921. The activity of IRA flying columns, such as the one under Tom Barry in West Cork, was popularised in the Ken Loach film The Wind That Shakes The Barley. On 11 December 1920 Cork City centre was gutted by fires started by the Black and Tans in reprisal for IRA attacks. Over 300 buildings were destroyed, many other towns and villages around the county suffered a similar fate including Fermoy.
During the Irish Civil War (1922–23), most of the IRA units in Cork sided against the Anglo-Irish Treaty. From July to August 1922 they held the city and county as part of the so-called Munster Republic. However, Cork was taken by troops of the Irish Free State in August 1922 in the Irish Free State offensive, that included both overland and seaborne attacks. For the remainder of the war, the county saw sporadic guerrilla fighting until the Anti-Treaty side called a ceasefire and dumped their arms in May 1923. Michael Collins, a key figure in the War of Independence, was born near Clonakilty and assassinated during the civil war in Béal na mBláth, both in west Cork.
Cork's Hurlers and Gaelic footballers still proudly carry the mantle of 'Rebels'.