| Operation Ironside | |
|---|---|
| Part of Operation Bodyguard | |
 Ironside was one of several plans within the larger Operation Bodyguard deception (contemporary boundaries shown). | |
| Operational scope | Political deception |
| Location | |
| Planned | December 1943 – March 1944 |
| Planned by | London Controlling Section |
| Target | Bordeaux |
| Date | May–July 1944 |
| Executed by | Agents Bronx, Tate, Rudloff and Garbo |
Operation Ironside was a Second World War military deception undertaken by the Allies in 1944. It formed part of Operation Bodyguard, a broad strategic deception plan instigated by the Allies throughout the year to help cover the June 1944 invasion of Normandy. Ironside supported the overall deception by suggesting to the Germans that the Allies would subsequently land along the Bay of Biscay. It complemented efforts to deceive the Germans into believing that the Allies would also land in southern France at this time (Operation Vendetta). Bordeaux was an important port for the German war effort and had already been a target of commando raids two years earlier. Ironside intended to play on German fears of an invasion in the region, with the aim of tying down defensive forces following Operation Overlord in June 1944.
Planned by the London Controlling Section, Ironside was communicated to the Germans via double agents between May and June 1944. Unlike other Bodyguard deceptions, the plan was put across entirely by double agents without support by physical deception. Agent Bronx took the lead with support from Tate, Rudloff and Garbo. Ironside's story included an initial two-division assault, using Overlord formations, staged out of the United Kingdom. This would then be followed up with six divisions sailing from the east coast of the United States. Historians disagree on the impact of Ironside on German plans. There is no indication that the operation was successful in convincing the Germans of imminent Allied plans to invade the Bay of Biscay. On the other hand, Allied planners attributed the delay of a panzer division moving to Normandy in part to the deception.
As Ironside was a marginal operation, and they were worried about exposing agents as false, the Twenty Committee for the most part used less important agents and added words of caution to the messages they sent, reducing the impact of the story. Allied landings around Bordeaux may also have seemed implausible because it was beyond air cover from the UK and lacked the normal physical elements (such as naval activities and dummy landing craft) associated with an invasion.
After the operation closed, at the end of June 1944, the threat of invasion from the United States was informally kept alive. It was revisited as Ironside II in mid-July as support for Operation Ferdinand. The invasion story was replaced with a supposed Allied plan to increase French resistance in the Bordeaux region to tie up German forces. Most of Ironside II was ignored by the Germans, whose interest had turned away from the region.