1944 MI5 Report Warned of Possible, but Unrealized, German Airborne Raid Targeting Royals or Churchill

Newly declassified documents have revealed that Britain's security service issued a covert alert in December 1944 warning of a possible Nazi plot to kill members of the Royal Family or Prime Minister Winston Churchill. The intelligence assessment, prepared jointly by MI5 and the Air Ministry, raised fears that Germany could deploy elite airborne troops on English soil with assassination as their objective.

The warning came just days after Adolf Hitler launched his unexpected military offensive through the Ardennes forest in Belgium.

That assault became known as the Battle of the Bulge and caused considerable alarm among Allied forces. According to the MI5 and Air Ministry intelligence report, the Germans possessed the capability to mount an assault force comprising as many as 500 paratroopers transported aboard twelve large Junkers Ju 290 aircraft.

An alternative method of attack involved seized American B-17 Flying Fortress and B-24 Liberator bombers flown by the Luftwaffe's specialist KG200 unit.

The KG200 squadron was a special flying unit typically tasked with dropping agents behind Allied lines and was known to operate captured foreign aircraft of various types. The report noted that deploying fewer aircraft would improve their chances of evading British defences.

Sir Samuel Findlater Stewart, a senior civil servant with established MI5 connections, conveyed the intelligence assessment to Gen Colin Callander, deputy chief of Home Defence Forces, on 20 December 1944.