Piracy is an act of robbery or criminal violence by ship or boat-borne attackers upon another ship or a coastal area, typically with the goal of stealing cargo and valuable goods, or taking hostages. Those who conduct acts of piracy are called pirates, and vessels used for piracy are called pirate ships. The earliest documented instances of piracy were in the 14th century BC, when the Sea Peoples, a group of ocean raiders, attacked the ships of the Aegean and Mediterranean civilisations. Narrow channels which funnel shipping into predictable routes have long created opportunities for piracy, as well as for privateering and commerce raiding.
Historic examples of such areas include the waters of Gibraltar, the Strait of Malacca, Madagascar, the Gulf of Aden, and the English Channel, whose geographic structures facilitated pirate attacks. The term piracy generally refers to maritime piracy, although the term has been generalized to refer to acts committed on land, in the air, on computer networks, and (in science fiction) outer space. Piracy usually excludes crimes committed by the perpetrator on their own vessel (e.g. theft), as well as privateering, which implies authorization by a state government.