His elder brother Conrad inherited the County of Luxemburg and became a faithful supporter of the Salian king Henry IV of Germany in the Investiture Controversy and the civil war of the Great Saxon Revolt.

While Henry turned to Italy in order to enforce his coronation in Rome, the Saxon and Swabian nobles led by the deposed Bavarian Duke Welf I elected Hermann as the second anti-king opposed to the Salian monarch in Ochsenfurt, Franconia on 6 August 1081.

He immediately entered into an armed conflict with the loyal Hohenstaufen duke Frederick of Swabia and retired to the Saxon lands, where Archbishop Siegfried of Mainz crowned him king in Goslar on 26 December.

He gained broad support by the Saxon nobility, however, his plan to gather an army on the banks of the Danube and march across the Alps into Italy was dashed by the death of his main retainer, Count Otto of Nordheim.

[5] He died near the Imperial castle of Cochem later that year of 1088 in a skirmish with his relative Count palatine Henry of Laach, ending the Great Saxon Revolt.