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.
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.
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.
With the end of the war and the removal of Churchill from office, MD1 was taken over by the Ministry of Supply and the Weapons research establishment at Fort Halstead with the result that it was disbanded.