Duke Berthold III was a notable nobleman from the House of Zähringen, ruling in the 12th century. He was born around 1140 and became the Duke of Zähringen after his father, Berthold II. His reign was marked by efforts to expand his territory and influence in the region of Swabia and Baden. Berthold III is also known for his role in the political landscape of the Holy Roman Empire. He was involved in various alliances and conflicts, particularly with the Hohenstaufen dynasty. His legacy includes the founding of several towns, contributing to the development of the region during his time.