An excerpt from the 2005 book State of Exception which serves as a good introduction to Agamben’s recent work on the nature of state power/sovereignty, as well as his dense and difficult style (5,000 words).
(…) We have already seen how the state of siege had its origin in France during the Revolution. After being established with the Constituent Assembly's decree of July 8, 1791, it acquired its proper physiognomy as état de siège fictif or état de siège politique with the Directorial law of August 27, 1797, and, finally, with Napoleon's decree of December 24, 1811.