What if...Muhammed was born 400 years earlier (in 171 instead of 571). Let's say that he archieved the same things as in real life: he made enemies and friends, he united the Arabians. What if his successors managed to gather enough support, money and an army to fight the Romans? Let's say that the Muslims would meet the Romans in battle the first time in 250. Would the Romans win? Both sides would be stern, they wouldn't give up fighting. Would the Muslims win after decades, when the Roman empire started to weaken more and more? Or would the Romans gather an army, to crush the muslims?
EDIT: sorry, I posted it in the wrong section. Should be in VV.