You might not have heard of the British Army’s “The Det” before, and you haven’t for a reason. They were part of the Intelligence Operations tasked to conduct undercover surveillance operations in Northern Ireland back in the 1970s. No one knew who exactly they were or what they did, as these plain-clothed cooperatives accomplished their tasks in the shadow. Here’s what we know about them:

Formed During The Troubles

 14th Intelligence Detachment, simply known as The Det, was formed during The Troubles, a period of violence in Northern Ireland when bombings, riots, and revenge killings were prominent due to the centuries-long conflict between the predominantly Catholic Ireland and the Protestants of England. The violence resulted in 3,600 deaths and around 30,000 injuries; the period lived up to its name.

A Belfast man on patrol for the Irish Republican Army, 1987. (Pacemaker Press International: Belfast Telegraph Archive/History Collection)

Before The Det, there was a unit called the Military Reaction Force (some sources referred to them as Military Reconnaissance Force or Mobile Reconnaissance Force). They were the ones conducting undercover military surveillance in Northern Ireland. Everything was going well, and they had their successes until two IRA double-agents working for the MRF were discovered and interrogated by the Provos, spilling the beans and compromising the MRF’s secret operation running out of the Four Squares laundry in Belfast. Naturally, they used the information they gathered to ambush an MRF laundry van, killing one of the agents.

NORTHERN IRELAND. Belfast. 1971. A British soldier speaking with a young boy. Usually, children and soldiers are on opposite sides during street riots. (Bruno Barbey/History Collection)

The Successor of the MRF

The Det was set up in 1973 after it was decided to establish a dedicated force of highly-trained plain-clothes surveillance operatives for  Northern Ireland operations. It was opened to all members of the armed services and both genders, a first for women allowed to become members of a UK Special Forces unit. The candidates had to go through and pass a rigorous selection process that screened for: excellent observational abilities, stamina, and the ability to think under stress, as well as self-reliance and self-confidence in carrying out operations alone. These were some of the skills that they were taught: