Berthold IV, Duke of Zähringen
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.
Conrad I, Duke of Zähringen
Conrad I, Duke of Zähringen (– 8 January 1152 in Constance) was Duke of Zähringen from 1122 until his death and from 1127 also Rector of Burgundy.
He spent most of his life stemming the growing power of the House of Hohenstaufen and to this end, allied himself with the House of Guelph.
Konrad the Curly
Konrad the Curly( c. 1198 – 4 September 1213 in Czerwony Kosciol), was a Polish prince member of the Piast dynasty in his Silesian branch.
He was the third son of Henry I the Bearded, Duke of Wroclaw, by his wife( and later Saint) Hedwig, daughter of Berthold IV, Duke of Merania.
Berthold V, Duke of Zähringen
Berthold V( 1160 – 18 February 1218 in Freiburg im Breisgau), also known as Bertold V or Berchtold V, was Duke of Zähringen until his death.
He was the son of Berthold IV and Heilwig of Frohburg.
Clementia of Zähringen
Clementia of Zähringen( unknown – 1175), was a daughter of Conrad I, Duke of Zähringen and his wife Clementia of Namur.
By her first marriage, Clementia was Duchess of Bavaria and Saxony.
By her second marriage she was Countess of Savoy.
Berthold III, Duke of Zähringen
Berthold III, Duke of Zähringen( b. c. 1085, d. 3 December 1122) was Duke of Zähringen from 1111 until his death.
He was the son of Berthold II( c. 1050 – 1111), the first holder of the ducal title.
Berthold III was a supporter of emperor Henry V and was significantly involved in the Concordat of Worms of 1122.
He was married to Sophia of Bavaria, a daughter of Henry IX, Duke of Bavaria.
He was killed on 3 December 1122 near Molsheim in the course of a feud, and was buried at St. Peter Abbey.
He died without male issue, and was succeeded by his brother, Conrad I( c. 1090 – 1152).
Berthold II, Duke of Carinthia
Berthold II, Duke of Carinthia( c. 1000 – 6 November 1078), also known as Berthold I of Zähringen, was a progenitor of the Swabian House of Zähringen.
From 1061 until 1077, he was the Duke of Carinthia and Margrave of Verona.
Adalbert I, Duke of Teck
Adalbert I, Duke of Teck was a German nobleman.
After the death of his brother Berthold IV, he styled himself" Duke of Teck", and thus founded the elder line of the Dukes of Teck, which existed until 1439.
Rudolf of Zähringen
Rudolf of Zähringen( also" RudolphRalph" or" Raoul")( c. 1135 – 5 August 1191) was the archbishop of Mainz from 1160 to 1161 and prince- bishop of Liège.
He was the son of Conrad I of Zähringen and Clemence of Luxembourg- Namur.
After the death of Arnold of Selenhofen, the citizens of Mainz elected him archbishop, but the city had been placed under the interdict and the aristocracy and clergy had fled to Frankfurt am Main, where they elected Christian of Buch instead.
Neither election was recognised by the emperor, Frederick Barbarossa.
At the Synod of Lodi, both archbishops- elect were deposed and Rudolf was excommunicated.
In 1167, already released from his excommunication, he became bishop of Liège, a position almost as secularly important as that of Mainz.
As bishop, he supported his brother, Berthold IV, Duke of Zähringen.
On 11 May 1188, he arrived at the Siege of Acre with an army.
He died on the way back from the Crusade, at Herdern.
He was buried in the monastery of Saint Peter's there.
Agnes of Rheinfelden
Agnes of Rheinfelden(*; † 19 December 1111) was the daughter of Rudolf of Rheinfelden, and the wife of Berthold II of Zähringen.

Question: When did Berthold Iv, Duke Of Zähringen's father die?
Answer: 8 January 1152