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 is sometimes described as an "irregular war" or "low-level war". The conflict 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 Regiment (UDR) was an infantry regiment of the British Army established in 1970, with a comparatively short existence ending in 1992. Raised through public appeal, newspaper and television advertisements, their official role was the "defence of life or property in Northern Ireland against armed attack or sabotage" but unlike troops from Great Britain they were never used for "crowd control or riot duties in cities". At the time the UDR was the largest infantry regiment in the British Army, formed with seven battalions plus another four added within two years.