The White Lady spy net stretched across Europe, encompassing more than
one thousand agents and producing 70 percent of Allied intelligence on
the German forces in the First World War. Through sheer ingenuity, it
maintained a staggeringly complex network of spies deep behind enemy
lines, who provided vital information on troop movements to and from the
Western Front. Its success rested on one man: Henry Landau.
After the war, Captain Henry Landau left the Service and during the
1930s wrote several books about his time as a spy, published only in the
United States to avoid prosecution under the United Kingdom Official
Secrets Act.