RAF Habbaniya was a large airbase constructed before the Second World War on the banks of the Euphrates. The waters of the Euphrates fed a lake that was used for landing flying boats. During the 1950s it was host to 276 Signals Unit which conducted sigint. It was also employed for airborne sigint flights over the Middle East and as far afield as the Caspian Sea. The co-located 123 Signals Unit did ground radar interception. In 1959, a violent coup against the Iraqi Royal Family led to the eviction of British units from Iraq. Thereafter these units operated from RAF Pergamos on Cyprus.
The relevant TNA files include: AIR 20/10328, AIR 20/10769, AIR 20/10932, AIR 20/11067, AIR 29/3027, AIR 29/3389, FO 371/141023, T 225/753