The Norman invasion of the late 12th century marked the beginning of more than 800 years of direct English rule and, later, British involvement in Ireland. In 1177 Prince John Lackland was made Lord of Ireland by his father Henry II of England at the Council of Oxford. The Crown did not attempt to assert full control of the island until the rebellion of the Earl of Kildare. Henry VIII proclaimed himself King of Ireland and also tried to introduce the English Reformation, which failed in Ireland. Attempts to either conquer or assimilate the Irish lordships into the Kingdom of Ireland led to a series of Irish military campaigns between 1534 and 1603. As the military and political defeat of Gaelic Ireland became more pronounced in the early seventeenth century, sectarian conflict became a recurrent theme in Irish history.
The 1614 overthrow of the Catholic majority in the Irish Parliament was realized principally through the creation of numerous new boroughs which were dominated by the new settlers. The Irish Parliament was abolished from 1 January 1801 in the wake of the republican United Irishmen Rebellion and Ireland became an integral part of a new United Kingdom of Great Britain and Ireland under the provisions of the Acts of Union 1800.
The Irish Parliamentary Party strove from the 1880s to attain Home Rule through the parliamentary constitutional movement, eventually winning the Home Rule Act 1914, although this Act was suspended at the outbreak of World War I. The Easter Rising staged by republicans two years later brought physical force republicanism back to the forefront of Irish politics.
In 1922, after the Irish War of Independence and the Anglo-Irish Treaty, most of Ireland seceded from the United Kingdom to become the independent Irish Free State, which after the 1937 constitution, began to call itself Ireland. The six northeastern counties, known as Northern Ireland, remained within the United Kingdom. The Irish Civil War followed soon after the War of Independence. The history of Northern Ireland has since been dominated by sporadic sectarian conflict between (mainly Catholic) Irish nationalists and (mainly Protestant) unionists. This conflict erupted into the Troubles in the late 1960s, until peace was achieved with the Belfast Agreement thirty years later.