On April 30, 1980, a group of six Iranian terrorists stormed the Iranian Embassy in London and took the diplomatic staff and several bystanders hostages.

The hostage-takers were members of an obscure Arab terrorist organization who opposed Ayatollah Khomeini and wanted Iran to give autonomy to Arabistan, or Khuzestan Province, a small but oil-rich province in southwest Iran.

Their intrusion began an ordeal that would end with a spectacular raid by the U.K.’s top special operations unit, the Special Air Service (SAS), on May 5.

In a first, the rescue was captured on live television, giving the SAS, which was created during World War II, newfound fame.

The advent of international terrorism as a form of political pressure in the 1970s pushed the SAS to shift from its focus on direct-action and reconnaissance to specializing in counterterrorism and hostage rescue.

Hostage rescue is one of the toughest special-operations mission-sets, as it requires not just reconnoitering an area and neutralizing an enemy but also applying surgical force when and where necessary so hostages aren’t harmed.

A Long Six Days

Iranian Embassy siege Operation Nimrod
A police officer on a ladder points his gun over a wall toward the Iranian Embassy in London, April 30, 1980. (Associated Press)

Within minutes of the terrorists’ intrusion, the SAS had been notified and spun up. With the motto “prior planning and preparation prevents piss-poor performance,” or the Seven Ps, the SAS operators got to work.

The SAS always has a squadron on standby for counterterrorism contingencies, with the assignment rotating among the unit’s squadrons. The task of responding to the embassy fell to B Squadron, which was the team on a 30-minute standby for such contingencies.