| Berthold IV | |
| Duke of Zähringen | |
| Noble Family: | Zähringen |
| Father: | Conrad I, Duke of Zähringen |
| Mother: | Clementia of Luxembourg-Namur |
| Spouse: | Heilwig of Frohburg Ida, Countess of Boulogne |
| Issue: | Berthold V |
Berthold IV, Duke of Zähringen ( - 8 December 1186) was a Duke of Zähringen and Rector of Burgundy. He was the son of Conrad I, Duke of Zähringen and Clementia of Luxembourg-Namur. He founded numerous cities, including Fribourg.
Berthold IV succeeded his father, Conrad I, in 1152 as Duke of Zähringen. Berthold also claimed the title of "Duke of Burgundy", which he had agreed upon with Barbarossa to receive after conquering the Cisjuran ("French") territories of Burgundy together and also helping him out in his Italian campaign in 1152. However, the conquest of Burgundy failed and in 1156 the Emperor Frederick Barbarossa instead married Beatrice, the daughter of the last Count of Burgundy of the House of Ivrea. This interfered with Berthold's claims and Berthold was given the title of Rector of Burgundy and was made overlord over the Transjuran ("Swiss") parts of Burgundy, Geneva, Lausanne and Sion.
The rivalry with Duke Frederick IV of neighbouring Swabia caused him to fight on the side of Welf VI in the Feud of Tübingen (1164-1166). In 1173, he became overlord of Zurich.
An entry in the necrology of the Abbey of Saint Peter in the Black Forest reads Latin: Berchtoldus 4. dux de Zaeringen, officium cum 5 candelis. Depositio Iohannis Tüfer abbatis: "Berthold IV, Duke of Zähringen donated 5 candles for the memory of John the Baptist".[1]
Berthold IV was married to Heilwig of Frohburg, with whom he had three children: