1-156-433 - Ann Ronan Picture Library/Heritage-Images

Frederick William, Elector of Brandenburg and Duke of Prussia, 17th century. Frederick William (1620-1688) became Elector of Brandenburg in 1640. Known as the 'Great Elector', he was responsible for regaining Brandenburg's territories which had been lost in the Thirty Years War. His legacy of a standing army, sound finances and efficient administration laid the foundations for the emergence of Prussia as the dominant German state.