Duke Charles I of Brunswick, also known as Charles I of Brunswick-Wolfenbüttel, was a German nobleman born in 1713. He ruled the Duchy of Brunswick-Wolfenbüttel from 1735 until his death in 1780. Charles was known for his military service and his efforts to modernize his duchy, including improvements in infrastructure and administration. He was a member of the House of Welf, a prominent dynasty in European history. Charles I's reign was marked by his involvement in various military campaigns, including the Seven Years' War, which significantly influenced European politics during the 18th century.