In 817, he was made Count of Brescia, Parma, Piacenza, Modena, and Bergamo. He was also made a missus dominicus, along with the Brescian bishop Ratald, for Italy. In 818, he was instrumental in putting down the rebellion of Bernard against the Emperor, Louis the Pious. In 822, after the abdication and death of Duke Winiges, Suppo was created Duke of Spoleto by the grateful emperor and he passed Brescia to his son Mauring. Suppo's death was recorded by Einhard and Spoleto went to Adelard, who died within five months, leaving the duchy to Mauring, Duke of Spoleto.
- Wickham, Chris. Early Medieval Italy: Central Power and Local Society 400-1000. MacMillan Press: 1981.
| Duke of Spoleto