Duke Berthold IV was a prominent nobleman from the House of Zähringen, ruling in the 12th century. He was born around 1160 and became Duke of Zähringen after his father's death. Berthold IV is known for his efforts to expand his territory and influence in Switzerland and Germany. He played a significant role in the political landscape of his time, often engaging in alliances and conflicts with other nobles. Berthold IV's reign was marked by his support for the Holy Roman Empire and his involvement in various military campaigns, which helped shape the region's history.