In December 998, Otto appointed his childhood companion Adhemar as duke.
Otto then took him south and they marched on Capua, where Laidulf, the reigning prince, was removed from his position for the assassination of his brother.
They then marched on Naples and took Duke John IV captive to Capua.
Laidulf, along with his wife Maria and Gaideris and Lando of Caiazzo, were exiled from the city and Adhemar was left in charge.
As prince, however, he did create Atenulf as count of Aquino, thus inaugurating that dynasty.