MD1

Ministry of Defence 1 (MD1), also known as "Churchill's Toyshop", was a British weapon research and development organisation of the Second World War.

Its two key figures were Major Millis Jefferis and Stuart Macrae, former editor of Armchair Science magazine.

MD1 began in the "Military Intelligence Research" (MIR). The MIR was a department of the War Office set up in 1939 under Lt-Col Joe Holland RE. Holland was the General Staff Officer Grade 1 (GSO1) and brought in Jefferis, also a sapper (RE), an explosives expert, with experience in India, as GSO2 to head MIR(c) a division of MIR that was to develop weapons for irregular warfare. Needing special magnets, Jefferis brought in Macrae initially as an outside contractor but later to be brought into uniform and serve as his deputy. Between them they produced the limpet mine, a timed explosive that could be stuck to the underside of a ship.

MIR(c) started in a room at the War Office, Macrae initially secured offices and workshop space at IBC, owners of Radio Normandie, in London. Macrae soon also secured all the staff, including Norman Angier who continued as Assistant Director and senior civilian throughout the war. Following an air raid, a large country house The Firs (fortunately the second home of a patriotic Major) was requisitioned and the design and workshops relocated there, in Whitchurch near Aylesbury in Buckinghamshire close to the Prime Minister at Chequers. There they developed and to some extent produced munitions.

During the phoney war, MIR(c) was engaged in developing the floating mine required for Churchill's planned Operation Royal Marine which aimed to disrupt German shipping in their inland waterways by dropping these mines into the river at Strasbourg.

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