Before Bletchley Park

The story of Bletchley Park's codebreaking operations in the Second World War is now well known, but its counterparts in the First World War – Room 40 & MI1(b) – remain in the shadows, despite their involvement in and influence on most of the major events of that war. From the First Battle of the Marne, the shelling of Scarborough, the battles of Jutland and the Somme in 1916, to the battles on th...