This volume covers European intelligence in the first half of the 20th century. It reveals that the Imperial German Government had a remarkable source at the Russian Embassy in London prior to the outbreak of the World War I; describes in detail Swedish-German cryptanalytical co-operation during the Great War in intercepting and solving Russian diplomatic telegram traffic; adds an intriguing new twist to the murder of the Tsar and his family; provides an authoritative account of Swedish cryptanalytical success against German and Soviet traffic during the World War II; and includes an anecdote...