Bertold III was a nobleman who held the title of Duke of Merania during the 13th century. He was part of the House of Andechs, a prominent family in medieval Germany. His reign was marked by efforts to expand his territory and influence in the region, which included parts of modern-day Austria and Slovenia. Bertold III was also known for his connections to the Holy Roman Empire, as he was involved in various political alliances and conflicts of the time. His leadership contributed to the development of the Duchy of Merania, which played a significant role in the history of southern Germany and its surrounding areas.