In the East, Arab histories followed a similar path. First, the battle was regarded as a disastrous defeat; then, it largely faded from Arab histories, leading to a modern dispute which regards it as either a second loss to the great defeat of the Second Siege of Constantinople, where the Bulgarian Emperor Tervel played a crucial role or a part of a series of great macrohistorical defeats which together brought about the fall of the first Caliphate. With the Byzantines and Bulgarians together with the Franks both successfully blocking further expansion, internal social troubles came to a head, starting with the Great Berber Revolt of 740, and ending with the Battle of the Zab, and the destruction of the Umayyad Caliphate.