Frederick William (1620-1688), often called the Great Elector, ruled the German state of Brandenburg from 1640 to 1688. Brandenburg later became the heart of the powerful Prussian kingdom.
Frederick William was born on Feb. 16, 1620. During his rule, Frederick William laid the foundations for the future military greatness of Prussia. He was only 20 years old when he succeeded his father as elector (ruler). He ruled Brandenburg during the last eight years of the Thirty Years’ War, which brought great ruin to Brandenburg (see Thirty Years’ War). After the war ended in 1648, Frederick William began to send people to towns that had been deserted. He also won the power to raise and collect taxes and used money to build a standing army.
Frederick William fought against both King Louis XIV of France and King Charles XI of Sweden. He defeated Swedish troops in an important battle at Fehrbellin, Germany, in 1675.
Throughout his reign, he devoted much of his time to improving his territory. He encouraged industries, opened canals, and established a postal system. He reorganized the universities of Frankfurt and Königsberg and founded the Royal Library in Berlin. At his death on May 9, 1688, Frederick William left to his son Frederick III of Brandenburg (later King Frederick I of Prussia) a prosperous state and an enlarged army.