The history of piracy dates back more than 3000 years, but its accurate account depends on the actual meaning of the word �pirate�. In English, the word piracy has many different meanings and its usage is still relatively new. Today, some uses of the word have no particular meaning at all. A meaning was first ascribed to the word piracy sometime before the XVII century. It appears that the word pirate (peirato) was first used in about 140 BC by the Roman historian Polybius. The Greek historian Plutarch, writing in about 100 A.D., gave the oldest clear definition of piracy. He described pirates as those who attack without legal authority not only ships, but also maritime cities. Piracy was described for the first time, among others, in Homer's The Iliad and The Odyssey. For a great many years there remained no unambiguous definition of piracy. Norse riders of the 9th and 11th century AD were not considered pirates but rather, were called "Danes" or "Vikings". Another popular meaning of the word in medieval England was "sea thieves". The meaning of the word pirate most closely tied to the contemporary was established in the XVIII century AD. This definition dubbed pirates "outlaws" whom even persons who were not soldiers could kill. The first application of international law actually involved anti-pirate legislation. This is due to the fact that most pirate acts were committed outside the borders of any country.