Backstory (Alternate 1400 Map Game)

POD - Early Middle Ages
The backstory starts with a fairly simple POD.

The POD begins when the Byzantine emperor mauritius isn't killed in the year 602, as he decides to make the army return to the winter quarters in the danube, this avoids the mutiny that sparked within the military.

Hence this, his reign lasts another five years, with him dying in 607 and keeping a more stable nation for a while, Khusrau II doesn't have a reason to launch an early attack on the Roman empire, thus preventing persia from getting any gain from the byzantine empire and thus avoiding the military exhaust that allowed the Muslim conquest to grow in the rather fast speed it did in OTL.

His son theodosius is proclaimed emperor, however his ruling means a certain success for the empires enemies as his loses italy and faces trouble in north africa as berbers attempt to gain control of the exarchate of Carthage. The persians attack the levant and egypt in 615 however their attempt fails, as the Byzantine army is not focused on a internal crisis like in OTL, instead they have both the strength and the force to push the persians back to the east.

The Byzantine empire stands strong by the time Islam arrives to the middle east horizon. Persia however isn't that strong, after the defeat of Khosrau's army by the byzantines, the persian nobles rise against the emperor forcing him to flee, in the midst of the civil war Persia loses its land in arabia and south of the tigris and euphrates.