Hermann is the founder of the House of Billung. There is doubt about Hermann's parents. They are unknown according to some sources while other sources have a Billung as his father and Ermengarde de Nantes as his mother. Hermann is generally counted as the first Billung Duke of Saxony, but his exact position is unclear. King Otto I appointed Hermann margrave in 936, granting him a march north of the Elbe between the Limes Saxoniae and Peene Rivers. Having more autonomy than his contemporary margrave Gero, Hermann exacted tribute from the Polabian Slavs inhabiting the March of the Billungs. He often fought against the West Slavic tribes of the Redarians, Abotrites, and Wagrians.
By 953 Otto I, who was also Duke of Saxony, began entrusting more and more of his authority in Saxony to Hermann during his absences. However, Hermann was never named as duke in royal documents. Instead, he is named as a military leader, count, and margrave. His son Bernard inherited and strengthened his father's position and managed to be recognized as duke.
Namesakes of Hermann Billung (c906-973)