Some idea of the enormous losses caused by them may be gathered from the fact that Bartholomew Roberts alone was credited with the destruction of four hundred trading vessels in three years.

In a single day he captured eleven vessels, English, French, and Portuguese, on the African coast.
War in Europe, and the financial exhaustion that ensued, rendered it almost impossible for the maritime powers to put an effective check on the pirates either in the East or the West.

With peace their numbers increased by the conversion of privateersmen into freebooters.

Slaver, privateers-man, and pirate were almost interchangeable terms.

At a time when every main road in England was beset by highwaymen, travellers by sea were not likely to escape unmolested.