Duke Charles IV of Brunswick (1804-1873) was a German nobleman and military leader. He was a member of the House of Welf and served as the Duke of Brunswick from 1830 until his death. Charles IV was known for his efforts to modernize the duchy and improve its infrastructure, including roads and education. During his reign, Charles IV faced political challenges, including conflicts with the Prussian government. He was also involved in the German Confederation, a loose association of German states. His leadership style was characterized by a commitment to both military and civic duties, leaving a lasting impact on the region.