WI: Lothair I wins the Battle of Fontenoy-en-Puisaye

In 841, Lothair I, Western/Holy Roman/Carolingian Emperor and King of Italy waged war alongside his nephew Pepin II of Aquitaine against the former's brothers, Charles the Bald and Louis the German in the Battle of Fontenoy-en-Puisaye. Historically, victory was given to Charles and Louis, which helped to divided Charlemagne's empire into West Francia (France), East Francia (Germany), and Middle Francia (Italy, Arles/Burgundy & Lotharingia)

But what if Lothair was able to win a decisive victory in Fontenoy, would Lothair be able to do what he envisioned and retain lordship over the entire Frankish domain? Would the Empire still collapse regardless of the battle?
 
Top