While Matilda and Theophanu stayed at the Italian court of Pavia in 984, the young girl was abducted by the forces of her quarrelling uncle Duke Henry II of Bavaria in 984 and held in custody by his henchman, the Billung count Egbert the One-Eyed.

In the German royal election of 1002 after the death of her brother Emperor Otto III, Adelaide and her older sister, Abbess Sophia of Gandersheim, acted as true kingmakers, having rejected Margrave Eckard of Meissen (who discounted their influence) as candidate for kingship.

Henry vested Quedlinburg Abbey with extended estates and in 1014 entrusted Adelaide with the administration of the convents in Gernrode, Frose and Vreden in Westphalia.

He repeatedly celebrated important feasts at Quedlinburg and in 1021 attended the consecration of the St Servatius Collegiate Church together with Archbishop Gero of Magdeburg.

The Princess-Abbess and her sister would play the same role in the election of Henry's Salian successor King Conrad II as Holy Roman Emperor in 1027.