The Barbary States, who were allies of the Ottoman Empire, sent Barbary pirates to raid parts of Western Europe in order to capture Christian slaves to sell at slave markets in the Arab World throughout the Renaissance period. Contemporaneous accounts suggest that a population of about 35,000 European slaves was maintained on the Barbary Coast. One writer estimates, on the basis that about 8,500 fresh slaves per annum would be required to maintain such a population, that as many as 1.25 million Europeans may have been taken in the 250 years to 1780, though there are no records to confirm such numbers. The slaves were captured mainly from seaside villages in Italy, Spain and Portugal, and from farther places like France or England, the Netherlands, Ireland and even Iceland and North America, ultimately provoking the First Barbary War of the newly-formed United States.