The purpose of this doctoral work is to consider ancient piracy over a long period of time, in the new light of the research recently carried out by N. Purcell and P. Horden on the ancient Mediterranean. This dissertation begins with a study of the Greek and Latin words related to piracy, and of the representation of the latter in ancient written sources. This work is completed by a new reading of the modern historiography, which needs to be examined in the light of its own historical context in order to dismiss the images commonly related to the notion of piracy. While piracy has so far been studied from a factual angle, this dissertation aims at focusing on the structures of ancient raid through a long-term perspective. This shift in perspective enables to consider pirates not simply as a negative side of maritime trade, but more deeply as agents of trade and as agents in the production of wealth. Through the in-depth study of two regions of the Mediterranean (Cilicia and the Balearic Sea), I wish to highlight the micro-local structures and the economic, social, territorial and geopolitical trends that enabled and sustained piracy. By the end of this study I wish to analyze piracy in all its diversity thanks to a new classification: the imagined pirate, the trading pirate and the opportunistic pirate.