I have been working out the parts to a new Timeline regarding an early Muslim invasion of Sicily and I've run into a bit of a speed-bump. Assuming that this invasion occurs in 741, Which is when Constantine V ascends to the throne, what would be Byzantine reaction to an Arab capture of Sicily and subsequent invasion of Reggio and the rest of Byzantine Italy? Considering he was going to invade Caliph Hisham, what would he do against the Arabs? In addition, what reaction would the Papacy have? Considering the Arabs would be fighting against The Lombards, would they have been pleased at this development?
Furthermore, how would this affect the plans of Aistulf, the reigning(and aggressive) Lombard king? Considering that he had ambitions over the Papal state and Ravenna, would he put aside this to fight the Arabs or ignore the pleas of the Duke of Benevento? This may be the case as the current Duke at the ascension of Aistulf was not approved by him, but perhaps I'm wrong.
Furthermore, how would this affect the plans of Aistulf, the reigning(and aggressive) Lombard king? Considering that he had ambitions over the Papal state and Ravenna, would he put aside this to fight the Arabs or ignore the pleas of the Duke of Benevento? This may be the case as the current Duke at the ascension of Aistulf was not approved by him, but perhaps I'm wrong.