Hostis humani generis

Hostis humani generis (Latin for 'an enemy of mankind') is a legal term of art that originates in admiralty law. Before the adoption of public international law, pirates and slavers were generally held to be beyond legal protection and so could be dealt with by any nation, even one that had not been directly attacked.

A comparison can be made between this concept and the common law "writ of outlawry", which declared a person outside the king's law, a literal out-law, subject to violence and execution by anyone. The ancient Roman civil law concept of proscription, and the status of homo sacer conveyed by proscription may also be similar.^[1]