Rgina Diana - Vivien Newman

The Untold Story of Rgina Diana tells of the rebellious daughter of working-class French-Italian parents from a run-down area of Geneva who, trained by the most ruthless spymaster of them all, Elisabeth Schragmller (aka Fraulein Doktor), became a much-adored French 'caf-concert' singer, a discreet and highly-prized prostitute plying her trade, and a successful German Great War spy.
Regina's spy operations were full of intrigue: a network spanning four countries based in the 'shamed' city of Marseille, with her performing abilities and sexual charms allowing her to lure men from privates to generals into giving her vital information.
This book is not just about Rgina, but also explodes the much-vaunted myth of Swiss neutrality. Switzerland, a nest of spies, was riven between support for Germany and France; in an extraordinary penetration of the upper echelons of Swiss society, the Swiss Army Commander-in-Chief was married to former German Chancellor Otto von Bismark's daughter.
Yet 'exhuming' Rgina from her unmarked grave involved a tantalising journey - getting past her disavowal by both France and Switzerland, unravelling the truth behind a three-line report about a "pretty Swiss singer's" execution and overcoming the obfuscation of French military archivists. Even her execution was fittingly exceptional. So determined were the French authorities that she should die, her firing squad numbered not the usual twelve, but twenty-five smoking rifles.