Charles I, Landgrave of Hesse-Kassel was born on November 3, 1654, in Kassel, Germany. He was the son of Landgrave Wilhelm VI and his wife Hedwig Sophia of Brandenburg. In 1670, Charles I became the regent of Hesse-Kassel after his father's death. He continued his father's military and political policies, including his alliance with Sweden and his support for Protestantism. Charles I also continued Hesse-Kassel's mercantilist policies, which helped to boost the state's economy. He encouraged the growth of industry and trade, and he built a network of roads and canals to facilitate commerce. In 1677, Charles I married his cousin, Maria Amalia of Courland. The couple had eight children, including four sons who would become landgraves of Hesse-Kassel. During the War of the Grand Alliance (1688-1697), Charles I fought on the side of the Grand Alliance against France. He commanded Hesse-Kassel's troops in several campaigns, including the Battle of Fleurus (1690) and the Siege of Namur (1692). After the war, Charles I continued to support Protestantism and Hesse-Kassel's economic growth. He died on May 23, 1730, in Kassel, at the age of 75.