As an example of the activities of the Austrian secret police under Emperor Francis II (I), we consider the surveillance of Louis Bonaparte (1778-1846), king of Holland, when he was in exile in Teplice. The Austrian secret police used several "tools" in the surveillance of persons who were or had aroused suspicion of being criminals or enemies of the state. The ministry of foreign affairs (Hof- und Staatskanzlei), the ministry of the interior (Oberste Polizeihofstelle) and the government of the states (Länder) worked together. The police paid "confidential people" (Vertraute) to observe the habits, activities and friends of the above categories of person. This work was done at the best-known spas by inspection commissioners who tended the patients and collected information. At the mail service letters from suspicious persons were secretly opened and copies were made. It is shown that these methods provided a fairly good picture of the person under surveillance, in our case the king of Holland., Friedrich Wilhelm Schembor., and Obsahuje bibliografické odkazy