Undercover work has been used in a variety of ways throughout the course of history, but the first organized, but informal, undercover program was first employed in France by Eugène François Vidocq in the early 19th century, from the late First Empire through most of the Bourbon Restoration. At the end of 1811, Vidocq set up an informal plainclothes unit, the Brigade de la Sûreté ("Security Brigade"), which was later converted to a security police unit under the Prefecture of Police. The Sûreté initially had eight, then twelve, and, in 1823, twenty employees.