Duke Charles I of Saxe-Weimar-Eisenach (1625-1683) was a German nobleman and a member of the House of Wettin. He ruled the duchy from 1662 until his death in 1683. Charles I is known for his efforts to promote education and culture in his territories, establishing schools and supporting the arts. During his reign, Charles I also focused on strengthening the economy and improving infrastructure. He was a patron of notable figures, including the composer Johann Sebastian Bach, who later became associated with the region. His leadership contributed to the development of Weimar as a cultural center in Germany.