Herman was born in Freiburg im Breisgau as the eldest son of Berthold I of Zähringen. He married Judit of Backnang-Sulichgau, Countess of Eberstein-Calw, who was the founder of Hirsau Abbey. From her, he obtained the right to Baden, which later became the core of the family dominions. Among those lands were the Frankish Albgau and Ufgau.
He and his wife founded the Augustinian monastery of Backnang Abbey. It quickly became dilapidated, and it was rebuilt by their son in 1123. Subsequently, the monastery was the resting place for five generations of the Margraves of Baden.
When Herman's father became Duke of Carinthia in 1061, Herman received the courtesy title of Margrave of Verona. While he never ruled in Verona, a dependency of Carinthia, the margravial title was to remain with his descendants. He was also count of the Breisgau.
Herman and Judit had the following children:
- Hermann II (d. October 8, 1130)
- Oexle, Otto Gerhard. "Hermann I." Deutsche Biographie (in German). Neue Deutsche Biographie (NDB). Retrieved 26 October 2017.