From Wikipedia

The Troubles

Episode Four

In 1968, the marches of the Northern Ireland Civil Rights Association (NICRA) were met with a violent backlash by police and civil authorities. This group had launched a peaceful civil rights campaign in 1967, which borrowed the language and symbolism of the Civil Rights Movement of Martin Luther King in the United States. NICRA was seeking a redress of Catholic and nationalist grievances within Northern Ireland. Specifically, they wanted an end to the gerrymandering of electoral constituencies that produced unrepresentative local councils (particularly in Derry City) by putting virtually all Catholics in a limited number of electoral wards; the abolition of the rate-payer franchise in local government elections, which gave Protestants disproportionate voting power; an end to unfair allocation of jobs and housing; and an end to the Special Powers Act (which allowed for internment and other repressive measures) which was seen as being aimed at the nationalist community.

Initially, Terence O'Neill, the Prime Minister of Northern Ireland, reacted favourably to this moderate-seeming campaign and promised reforms of Northern Ireland. However, he was opposed by many unionists, including William Craig and Ian Paisley, who accused him of being a "sell-out". Some unionists immediately mistrusted the NICRA, seeing it as an IRA "Trojan Horse".

Violence broke out at several civil rights marches when Protestant loyalists attacked civil rights demonstrators with clubs. The Royal Ulster Constabulary, almost entirely Protestant, was widely viewed by nationalists as supporting the loyalists and of allowing the violence to occur. On 5 October 1968, a Civil Rights march in Derry was banned by the Northern Ireland government. When Civil Rights activists defied the ban, they were attacked by the RUC, leading to three days of rioting. On 4 January 1969, a People's Democracy march between Belfast and Derry through Catholic and Protestant areas was repeatedly attacked by loyalists and off-duty police. At Burntollet bridge it was ambushed by ~200 loyalists armed with iron bars, bricks and bottles. The police did little to protect the march. Subsequently, barricades were erected in nationalist areas of Belfast and Derry to prevent police incursions. Many regard these events as the beginning of the Troubles.