Category: Postal Espionage

• The "Black Cabinet" (Cabinet Noir)

  This theory held that European states maintained hidden rooms inside their postal systems where officials secretly opened, copied, deciphered, and resealed private and diplomatic correspondence. Unlike many courtly conspiracy theories, this one turned out to be substantially true. Across early modern and nineteenth-century Europe, so-called black chambers or cabinet noirs operated as institutionalized mail-intelligence systems, especially in places such as France, Vienna, and elsewhere. The historical record clearly shows that diplomatic and even private letters were intercepted as a routine instrument of statecraft. What varied from country to country was not whether such systems existed, but how systematically and how secretly they were run.