The Scandinavian slave trade mainly occurred in the early history of Sweden when the trade of thralls (Old Norse: þræll) was one of the pillars of the Norse economy. During the raids, the Vikings often captured and enslaved militarily weaker peoples they encountered, but took the most slaves in raids of the British Isles and Slavs in Eastern Europe. This practice lasted in the 6th through 11th centuries until formally abolished in 1335. A smaller trade of African slaves happened during the 17th and 18th centuries, around the time Swedish overseas colonies were established in North America (1638) and in Africa (1650). It remained legal until 1813.