The Troubles [was a] violent sectarian conflict from about 1968 to 1998 in Northern Ireland between the overwhelmingly Protestant unionists (loyalists), who desired the province to remain part of the United Kingdom, and the overwhelmingly Roman Catholic nationalists (republicans), who wanted Northern Ireland to become part of the republic of Ireland. [...]
In 1920, during the Irish War of Independence (1919–21), the British Parliament, responding largely to the wishes of Ulster loyalists, enacted the Government of Ireland Act, which divided the island into two self-governing areas with devolved Home Rule-like powers. [...]
Thus, in 1922 Northern Ireland began functioning as a self-governing region of the United Kingdom. Two-thirds of its population (about one million people) was Protestant and about one-third (roughly 500,000 people) was Catholic. The divide between Catholics and Protestants in Northern Ireland had little to do with theological differences but instead was grounded in culture and politics. [...]
As the 1970s progressed, rioting became more common in Belfast and Derry, bombings of public places (by both loyalists and republicans) increased, and both sides of the conflict perpetrated violent, deadly atrocities. [...]
On January 30, 1972, the conflict reached a new level of intensity when British paratroopers fired on Catholic civil rights demonstrators in Londonderry, killing 13 and injuring 14 others (one of whom later died). The incident [...] became known as “Bloody Sunday.”