In an era of almost uninterrupted Arab expansion the Emperor Constantine IV put a check on the expansion of the Caliphate. The Emperor died at the age of 33, but what if he hadn't fallen ill and ruled for another 25 years. The basic idea is that Constantine doesn't leave before the Battle of Ongal and the army doesn't think that the emperor has fled and doesn't panic. The Romans manage to defeat the the Bulgars causing the break up of the Seven Slavic tribes and preventing the creation of the Bulgarian Empire before it could even form. This butterflies the dysentery that killed him and in 685 and instead he goes on to rule the empire for another twenty years.
So what does Constantine's continued rule and the prevention of the formation of the Bulgarian Empire mean for the Roman Empire? What does his continued rule and the lack of an organized enemy in the Balkans mean for the empire's dealings with the Caliphate? Can Constantine be an early Basil II? What happens to Roman Italy and North Africa in this situation?
So what does Constantine's continued rule and the prevention of the formation of the Bulgarian Empire mean for the Roman Empire? What does his continued rule and the lack of an organized enemy in the Balkans mean for the empire's dealings with the Caliphate? Can Constantine be an early Basil II? What happens to Roman Italy and North Africa in this situation?