Justitium

Justitium is a concept of Roman law, equivalent to the declaration of the state of emergency. It was usually declared following a sovereign's death, during the troubled period of interregnum, but also in case of invasions. However, in this last case, it was not as much the physical danger of invasion that justified the instauration of a state of exception, as the consequences that the news of the invasion had in Rome - for example, justitium was proclaimed at the news of Hannibal's attacks.

According to Giorgio Agamben, justitium progressively came to mean, at the end of the Roman Republic, the public mourning of the sovereign: a sort of privatization or diversion of the danger threatening the polis, as the sovereign claimed for himself the auctoritas necessary to the rule of law.