Wikipedia (en)
The Troubles (Irish: Na Trioblóidí) was an ethno-nationalist conflict in Northern Ireland during the late 20th century. Also known internationally as the Northern Ireland conflict, it is sometimes described as a "guerrilla war" or a "low-level war". The conflict began in the late 1960s and it is usually deemed to have ended with the Good Friday Agreement of 1998. Although the Troubles mainly took place in Northern Ireland, at times the violence spilled over into parts of the Republic of Ireland, England and mainland Europe.
The conflict was primarily political and nationalistic, fuelled by historical events. It also had an ethnic or sectarian dimension, although it was not a religious conflict. A key issue was the constitutional status of Northern Ireland. Unionists/loyalists, who are mostly Protestants and have British nationality (along with the rest of those from Northern Ireland), want Northern Ireland to remain within the United Kingdom. Irish nationalists/republicans, who are mostly Catholics, want Northern Ireland to leave the United Kingdom and join a united Ireland. The conflict began during a campaign to end discrimination against the Catholic/nationalist minority by the Protestant/unionist government and police force. This protest campaign was met with violence by loyalists who viewed it as a republican stalking horse. This eventually led to the deployment of British troops, initially to support the police and protect Catholic civilians, and the subsequent warfare over the next three decades.
The main participants in the Troubles were republican paramilitaries such as the Provisional Irish Republican Army (IRA) and the Irish National Liberation Army (INLA); loyalist paramilitaries such as the Ulster Volunteer Force (UVF) and Ulster Defence Association (UDA); British state security forces – the British Army and Royal Ulster Constabulary (RUC); and political activists and politicians. The security forces of the Republic played a smaller role. More than 3,500 people were killed in the conflict, of whom 52% were civilians, 32% were members of the British security forces, and 16% were members of paramilitary groups. There has been sporadic violence since the Good Friday Agreement was signed, including a campaign by anti-ceasefire republicans.