# House of Frohburg

The House of Frohburg (also Froburg) was a noble family in medieval Switzerland, with possessions in what is now the canton of Solothurn. They originate in the Wigger basin, near Zofingen. In the 10th century, they built Frohburg Castle on a hill near Trimbach. They had the title of counts from the later 11th century. They ruled the lands between Olten and Solothurn, and took parts of Aargau and Sisgau as fief from the bishop of Basel. They reached the peak of their power in the later 12th and early 13th century, building a number of castles, and founding towns such as Aarburg, Liestal, Olten (then a fortified river crossing), Waldenburg, Wiedlisbach and Zofingen. They also founded Schöntal Abbey near Waldenburg. The House of Frohburg was divided into three branches, Neu-Homberg, Waldenburg and Zofingen, in c. 1250. The Zofingen branch was extinct in 1307, followed by the Neo-Homberg one in 1325. The Waldenburg branch survived for another 40 years but declined in influence, being forced to sell most of its possessions, most of them to the ascending House of Habsburg. The last count of Frohburg was Hermann VI (d. 1367 as abbot of St. Urban's Abbey).

## Counts of Frohburg
### House of Frohburg
#### Partitions of Frohburg under House of Frohburg rule

County of Frohburg (1028-1213) :
| County of Zofingen (1213-1299) | | |
| County of Zofingen (1213-1299) | County of Waldenburg (1213-1367) | County of Homberg (1220-1303) |
| Annexed to the House of Habsburg | County of Waldenburg (1213-1367) | County of Homberg (1220-1303) |
| Annexed to the House of Habsburg | County of Waldenburg (1213-1367) | Annexed to the Bishopric of Basel |
| Annexed to the House of Habsburg | Annexed to the Bishopric of Basel and the County of Nidau | Annexed to the Bishopric of Basel |

#### Table of rulers

| Ruler | Born | Reign | Death | Ruling part | Consort | Notes |
| Adalbero (I) | ? | c.1028-1050? | ? | County of Frohburg | Unknown at least one child | First documented count of the family, in Breisgau. |
| Wolfrad | ? | c.1050-1095 | c.1095 | Frohburg | Unknown four children | Possibly sons of Adalbero. They may have ruled jointly. In 1114, another Volmar is mentioned, but is not identical with Volmar I. This new Volmar appears as co-ruler with Volmar I and his brother Louis. Louis' son, Ortlieb, would become Bishop of Basel. |
| Volmar I | ? | c.1050-1114 | 1114 | Frohburg | Sophia of Pfirt two children | Possibly sons of Adalbero. They may have ruled jointly. In 1114, another Volmar is mentioned, but is not identical with Volmar I. This new Volmar appears as co-ruler with Volmar I and his brother Louis. Louis' son, Ortlieb, would become Bishop of Basel. |
| Volmar (I) | ? | c.1095-1114 | c.1114 | Frohburg | Unknown | Possibly sons of Adalbero. They may have ruled jointly. In 1114, another Volmar is mentioned, but is not identical with Volmar I. This new Volmar appears as co-ruler with Volmar I and his brother Louis. Louis' son, Ortlieb, would become Bishop of Basel. |
| Louis I | ? | c.1095-1114 | c.1114? | Frohburg | Unknown one child | Possibly sons of Adalbero. They may have ruled jointly. In 1114, another Volmar is mentioned, but is not identical with Volmar I. This new Volmar appears as co-ruler with Volmar I and his brother Louis. Louis' son, Ortlieb, would become Bishop of Basel. |
| Adalbero I | ? | 1114-1152 | c.1152 | Frohburg | Sophia of Lenzburg four children | Sons of Volmar I, ruled jointly. |
| Herman I | ? | 1114-1125 | c.1125 | Frohburg | Unmarried | Sons of Volmar I, ruled jointly. |
| Volmar II | ? | 1152-1175 | c.1175 | Frohburg | Unknown four children | Sons of Adalbero I, possibly ruled jointly. Louis became Bishop of Basel in 1164. |
| Louis II | ? | 1152-1164 | March 1179 | Frohburg | Unmarried | Sons of Adalbero I, possibly ruled jointly. Louis became Bishop of Basel in 1164. |
| Herman II | ? | 1175-1213 | 1213 | Frohburg | A lady from the Kyburg family eight children | |
| Louis III | ? | 1213-1256/9 | 1256/9 | Frohburg-Zofingen | Gertrude of Habsburg six children | Children of Herman II, divided the land. Louis III was the founder of the Zofingen branch, with lands in the canton of Aargau. According to some theories, Gertrude, wife of King Rudolf I of Germany, was his daughter. Herman III founded the Waldenburg branch, with lands in the canton of Basel. The other two brothers did not take part on the divisions. One of them, Ulrich, pursued an ecclesiastical career being an abbot at Frienisberg Abbey. |
| Herman III | ? | 1213-1233/7 | 25 January 1233 or February 1237 | Frohburg-Waldenburg | Heilwig of Habsburg three children | Children of Herman II, divided the land. Louis III was the founder of the Zofingen branch, with lands in the canton of Aargau. According to some theories, Gertrude, wife of King Rudolf I of Germany, was his daughter. Herman III founded the Waldenburg branch, with lands in the canton of Basel. The other two brothers did not take part on the divisions. One of them, Ulrich, pursued an ecclesiastical career being an abbot at Frienisberg Abbey. |
| Volmar III | ? | 1213-1226 | 1226 | Frohburg | Unmarried | Children of Herman II, divided the land. Louis III was the founder of the Zofingen branch, with lands in the canton of Aargau. According to some theories, Gertrude, wife of King Rudolf I of Germany, was his daughter. Herman III founded the Waldenburg branch, with lands in the canton of Basel. The other two brothers did not take part on the divisions. One of them, Ulrich, pursued an ecclesiastical career being an abbot at Frienisberg Abbey. |
| Ulrich | ? | 1213-1223 | 1223 | Frohburg | Unmarried | Children of Herman II, divided the land. Louis III was the founder of the Zofingen branch, with lands in the canton of Aargau. According to some theories, Gertrude, wife of King Rudolf I of Germany, was his daughter. Herman III founded the Waldenburg branch, with lands in the canton of Basel. The other two brothers did not take part on the divisions. One of them, Ulrich, pursued an ecclesiastical career being an abbot at Frienisberg Abbey. |
| Louis IV | ? | c.1220-1257 | 1257 | Frohburg-Zofingen | Unmarried | Children of Louis III, probably divided fiefs in their father's lifetime: while Louis IV kept co-ruling with his father, Herman IV founded a new branch of the family at Homberg, by inheriting, through marriage, this land. |
| Herman IV & I | ? | c.1220-1253/6/9 | 15 May 1253 or 1256/59 | Frohburg-Homberg | A lady from the House of Homberg four children | Children of Louis III, probably divided fiefs in their father's lifetime: while Louis IV kept co-ruling with his father, Herman IV founded a new branch of the family at Homberg, by inheriting, through marriage, this land. |
| Louis V | ? | 1237 - 22 November 1279/81 | 22 November 1279/81 | Frohburg-Waldenburg | Agnes of Bechburg three children | |
| Hartmann I | ? | 1256/9-1281/5 | bet. 23 June 1281-6 December 1285 | Frohburg-Zofingen | Clementia before 1263 no children Ita of Wolhusen before 1280 three children | |
| Louis I | ? | 1253 - 27 April 1289 | 27 April 1289 | Frohburg-Homberg | Elisabeth of Rapperswil 15 February 1283 six children | Children of Herman IV/I, ruled jointly. Louis I possibly co-ruled with his wife in the County of Rapperswil. |
| Frederick | ? | 1253 - 8 February 1285 | 8 February 1285 | Frohburg-Homberg | Unmarried | Children of Herman IV/I, ruled jointly. Louis I possibly co-ruled with his wife in the County of Rapperswil. |
| Werner I | ? | 1253 - 6 February 1273 | 6 February 1273 | Frohburg-Homberg | Kunigunde two children | Children of Herman IV/I, ruled jointly. Louis I possibly co-ruled with his wife in the County of Rapperswil. |
| Herman V | ? | 22 November 1279/81 - 1291 | aft. 1 December 1291 | Frohburg-Waldenburg | Unmarried | Left no descendants. He was succeeded by his younger brother. |
| Louis VI | ? | 22 November 1281/5 - 1299 | aft. 5 July 1307 | Frohburg-Zofingen | Unmarried | Son of Hartmann I, left no descendants. In 1299 he sold Zofingen to the Habsburgs. |
| Zofingen annexed to the House of Habsburg ||||||||
| Werner II | 1284 | 27 April 1289 - 1303 | 21 March 1320 aged 35-36 | Frohburg-Homberg | Maria of Oettingen (d. 10 July 1369) 11 June 1315 or 6 April 1316 two children | Children of Louis I and Elisabeth of Rapperswil, ruled jointly with their cousin Herman II (son of Werner I). Werner inherited his mother's fiefs in the canton of Schwyz, and was also a Minnesinger. |
| Louis II | ? | 27 April 1289 - 1303 | 1315 | Frohburg-Homberg | Unmarried | Children of Louis I and Elisabeth of Rapperswil, ruled jointly with their cousin Herman II (son of Werner I). Werner inherited his mother's fiefs in the canton of Schwyz, and was also a Minnesinger. |
| Herman II | ? | 27 April 1289 - 1303 | 19 November 1303 | Frohburg-Homberg | Unmarried | Children of Louis I and Elisabeth of Rapperswil, ruled jointly with their cousin Herman II (son of Werner I). Werner inherited his mother's fiefs in the canton of Schwyz, and was also a Minnesinger. |
| Homberg sold to the Bishopric of Basel ||||||||
| Volmar IV | ? | 1291 - 20 January 1320 | 20 January 1320 | Frohburg-Waldenburg | Katharina of Toggenburg (d. 18 February 1313) three children | Left no descendants. He was succeeded by his younger brother. |
| John I | ? | 20 January 1320 - January/April 1366 | bet. 20 January - April 1366 | Frohburg-Waldenburg | Adelaide of Ramstein (d. bet. 17 October 1367-29 May 1371) 3 November 1326 no children | Sons of Volmar IV, probably ruled jointly. Herman was also abbot of St. Urban Abbey. After both deaths with no descendants, their line died out. Their properties were sold to the Count of Nidau and the Bishop of Basel. |
| Herman VI | ? | 20 January 1320 - 19 October 1367 | 19 October 1367 | Frohburg-Waldenburg | Unmarried | Sons of Volmar IV, probably ruled jointly. Herman was also abbot of St. Urban Abbey. After both deaths with no descendants, their line died out. Their properties were sold to the Count of Nidau and the Bishop of Basel. |
| Waldenburg annexed to the Bishopric of Basel and the County of Nidau ||||||||