His son, Count Gebhard III of Sulzbach, married Matilda, daughter of Henry IX, Duke of Bavaria.

[7] On 5 February 1104 Count Sigehard of Burghausen was murdered, and Henry IV, Holy Roman Emperor, was blamed for the crime.

[9] On 12 December 1104 King Henry V with a small retinue left his father's camp in Fritzlar and took refuge in Bavaria, the start of the rebellion.

Berengar was present at the emperor's funeral, and was one of the signatories to a letter inviting the leading men of the kingdom to attend a diet on 25 August 1125 to elect a successor.

[5] As one of the leaders of the ecclesiastical reform circle in Upper Bavaria, Swabia and Saxony Berengar was one of the founders of the Abbeys of Berchtesgaden, Kastl, and Baumberg.

According to legend, it was founded in fulfillment of a vow of thanksgiving for the salvation of his father, Gebhard II of Sulzbach, after a hunting accident at the rock on which the Berchtesgaden Collegiate Church stands today.

His mother Irmgard owned Berchtesgaden from her first marriage with Count Engelbert V of Chiemgau, and as his widow had made a vow to have a house built for use by an "assembly of clergy of communal life" ("congregatio clericorum communis vite").

Due to various worldly affairs Irmgard did not have the time to found the congregation, so shortly before her death she commissioned Berengar with the task, to promote his and her salvation.

[b][19] According to the Fundatio monasterii Berchtesgadensis the Augustinians at first found the lonely wilderness of Berchtesgaden, with its terrifying mountain forests, and permanent ice and snow a very inhospitable place, and sought somewhere more suitable.

Adelheid therefore felt compelled before her death (1104/1105) to place her husband and a dozen selected ministers under oath to establish a regular canons monastery to the north of lake Chiemsee and to annex the existing church of St. Margaret in Baumburg.

He therefore followed the urging of his church officials and expanded Baumburg with goods from Berchtesgaden so he would have at least one well-equipped monastery, and would meet the wishes of his mother and first wife.

After Berengar died in 1125, Gottschalk challenged the legality of the separation and asked Archbishop Conrad I of Salzburg for an injunction to re-merge the properties.