Upon his brother's death in 944, he also became count in the Saxon Bardengau around the town of Lüneburg, where he founded the monastery of St Michael in that city. He again disregarded the inheritance claims raised by his nephews Wichmann the Younger and Egbert the One-Eyed. In 953 both joined the countrywide rebellion started by King Otto's younger brother Duke Liudolf of Swabia, which only collapsed due to the massive invasion of Hungarian forces. During this grave crisis, the king, who was also Duke of Saxony, began entrusting more and more of his authority in the Saxon lands to Hermann during his absences. However, Hermann was never named "dux" in royal documents. Instead, he is named as a military leader, count, and margrave.