During the Second World War, Gibraltar faced the threat of invasion by Italy, Spain and Germany. The Abwehr, the German Intelligence Service, made numerous attempts to sabotage military installations and shipping with limited success. The Italians launched underwater attacks which were relatively successful and a number of attempts by Spanish Falangists failed. Using British Secret Intelligence Service and Special Operations Executive files from the National Archives, autobiographies, biographies and histories and newspaper articles, this documentary history investigates the successes and failures of over 70 attacks and the roles played by intelligence officers in discovering and preventing such acts. The book sheds light on an unusual and largely overlooked aspect of Gibraltar's history.