Karl I of Anhalt was a German nobleman who ruled as the Duke of Anhalt from 1252 until his death in 1260. He was a member of the House of Ascania, a prominent dynasty in medieval Germany. His reign was marked by efforts to consolidate power and manage the various territories under his control. During his rule, Karl I focused on strengthening the Anhalt region, which included several principalities. He worked to improve local governance and foster economic development, laying the groundwork for future stability in the area. His leadership contributed to the enduring legacy of the Anhalt duchy in German history.