Eugène François Vidocq, French detective, was born at Arras in 1775 (or possibly 1773). After an adventurous youth he joined the French army, where he rose to be lieutenant. At Lille he was imprisoned as the result of a quarrel with a brother officer, and while in gaol became involved, possibly innocently, in the forgery of an order for the release of another prisoner. He was sentenced to eight years' hard labour, and sent to the galleys at Brest, whence he escaped twice but was recaptured. For the third time he succeeded in getting free, and lived for some time in the company of thieves and other criminals in Paris and elsewhere, making a careful study of their methods. He then offered his services as a spy to the Paris police (1809). The offer was accepted, on condition that he should extend his knowledge of the criminal classes by himself serving a further term in prison in Paris, and subsequently Vidocq was made chief of the reorganized detective department of the Paris police, with a body of ex-convicts under his immediate command. In this capacity Vidocq was extremely successful for he possessed unbounded energy and a real genius for hunting down criminals. In 1827, having saved a considerable sum of money, he retired from his post and started a paper mill, the work people in which were drawn entirely from ex-convicts. The venture, however, was a failure, and in 1832 Vidocq re-entered the police service and was employed mainly in political work, though given no special office. Anxious to get back to his old detective post he himself foolishly organized a daring theft. The authorities were unable to trace the thieves, who at the proper moment were "discovered" by Vidocq. His real part in the matter became known, however, and he was dismissed from service. He subsequently started a private inquiry agency, which was indifferently successful, and was finally suppressed. Vidocq died in great poverty in 1857. Several volumes have been published under his name, the best known of which is _Mémoires de Vidocq_ (1828). It is, however, extremely doubtful whether he wrote any of them.