alternatehistory.com

On the death of Desiderio on 790, his grandson, Grimoaldo would take over the Lombard Kingdom of Italy, his first action was to marry his sister, Theoderada to Charles, one of the heir of the Frankish kingdom and married Epythimia of the Byzantine Empire and married Ida the only surviving child of Carloman to Constantine V, Grimoaldo would move his capital to Rome despite the pope’s objections.

Epythimia and Grimoaldo would have two known children namely Arechi (792) and Maria(800).

Grimoaldo’s intrigues and the marriage of Theoderada to Charles would succeed when Charles I of Francia died on 814 as Francia is divided into two, Burgundy and Aquitaine went to his son Charles with Borges as Capital with his realm later called as the Kingdom of Aquitaine and Louis would have Eastern Francia with Regensburg as the Capital which would be called as the Kingdom of Germany and Neustria would be disputed between the two causing the Frankish realm to be unstable with the Italians benefiting and Grimoaldo I of Italy and Emperor Constantine VI playing the two brothers against each other which would continue even after his reign as his daughter Maria would marry Lothari I of Aquitaine, the son of Charles II of Aquitaine.