The Troubles: Three members of the Ulster Defence Association opened fire in a crowded pub during a Halloween party, killing eight people and wounding nineteen others.

The Troubles were an ethno-nationalist conflict in Northern Ireland that lasted for about 30 years from the late 1960s to 1998. Also known internationally as the Northern Ireland conflict, it began in the late 1960s and is usually deemed to have ended with the Good Friday Agreement of 1998. Although the Troubles mostly took place in Northern Ireland, at times violence spilled over into parts of the Republic of Ireland, England, and mainland Europe.

The Ulster Defence Association (UDA) is an Ulster loyalist paramilitary group in Northern Ireland. It was formed in September 1971 as an umbrella group for various loyalist groups and undertook an armed campaign of almost 24 years as one of the participants of the Troubles. Its declared goal was to defend Ulster Protestant loyalist areas and to combat Irish republicanism, particularly the Provisional Irish Republican Army (IRA). In the 1970s, uniformed UDA members openly patrolled these areas armed with batons and held large marches and rallies. Within the UDA was a group tasked with launching paramilitary attacks that used the cover name Ulster Freedom Fighters (UFF) so that the UDA would not be outlawed. The British government proscribed the UFF as a terrorist group in November 1973, but the UDA itself was not proscribed until August 1992.

The Greysteel massacre was a mass shooting that took place on the evening of 30 October 1993 in Greysteel, County Londonderry, Northern Ireland. Members of the Ulster Defence Association (UDA), a loyalist paramilitary group, opened fire on civilians in a crowded pub during a Halloween party, killing eight and wounding nineteen. The pub was targeted because it was frequented by Catholics, though two of the victims were Protestant. The group claimed responsibility using their cover name "Ulster Freedom Fighters", saying the attack was revenge for the Shankill Road bombing by the Provisional IRA a week earlier. Four men were sentenced to life imprisonment for the massacre but were released in 2000 under the terms of the Good Friday Agreement.