As someone who has encountered no credible evidence that the protagonist of the Christian gospels ever existed, I have decided to treat reports of his activities as historical myth.  And having now done some reading (but no where near the amount or extent I've done on the Jesus Myth) I see no reason why this same stance should not be taken in respect to Mohammed and accounts of the history of early Islam.

The generally accepted history - written hundreds of years after the events it reports -- is that a couple of years after the death of an Arab named Mohammed (632 CE), the Arabs, enthused in their new religion, poured out of the Arabian peninsula and quickly subjugated the Near East and Egypt.

I have searched the internets for any contemporaneous account of this conquest and have come up empty.  One would have thought that the affected empires, the Byzantine and the Sassanid, would have noticed, but neither seems to have.  And the story makes no sense given what we do know of the history of the Near East.

For hundreds of years Arabs had lived sedentary rural lives within the bounds of the Roman and Byzantine Empires (Southern Syria and Eastern Palestine) and the Sassanid Empire (West of the Euphrates).  They provided defenses against border brigandage and troops at times of war.  In the Seventh Century they were the Gassanids and the Lakhmids and lived, here.  Both groups were Christians, Monophysites and Nestorians, heretics as far as Byzantium was concerned.  What would make anyone think that these Arab Christians would, overnight, abandon their faith and become Muslims?  Or that a bunch of ragtag pastoralists would overwhelm these warrior societies?

I am most intrigued by the claim that a mighty battle took place between the Byzantine army and these Muslim peninsular Arabs "over six days in August 636, near the Yarmouk River" at which the Byzantines were routed and forced out of Syria and Palestine forever.  The <i>Wikipedia</i> entry provides an exhaustive description.  Who could doubt its veracity?

And yet, the notes reveal that the primary source is a Persian historian named "al-Tabari" (838-923 CE), who is said to have relied upon one "Ibn Ishaq" (died 767c.).  Both men were hagiographers of Islam's founders and of the Arab race (bias), and for neither were the events contemporaneous.  As I noted above with the respect to the broader "conquest," here, also, I've searched and have found no contemporary report of this battle.

Does anyone have better information?  Is this simply an example of the historical myth of Islam?