What happens if the Seljuk Turks invade Fatimid Egypt instead of fighting at Manzikert?

[Slaytaninc]

As it says on the tin, what happens?

I think it is safe to assume that the Seljuks will tie down a good part of their army in taking Egypt.

However, the Byzantine theme system was by this time a rotting corpse, and I think SOMEONE will kick it in, even if not the Great Seljuk Empire.

[hellheaven1987]

Crusader would have better surviving rate in Middle East.

[Tiberios]

As it says on the tin, what happens?

I think it is safe to assume that the Seljuks will tie down a good part of their army in taking Egypt.

However, the Byzantine theme system was by this time a rotting corpse, and I think SOMEONE will kick it in, even if not the Great Seljuk Empire.

Well without the defeat at Manzikert, Emperor Romanos IV Diogenes might have reuilt the theme system. Or perhaps later emperors would.

[Faramir D'Andunie]

Two possible outcomes in my mind, concerning the empire.

The most unlikely one, Romanos Diogenes manages to hold the throne long enough to weaken the bureaucrats in Constantinope and perhaps (rather big perhaps) witness the rise of emperors willing to reform the theme system/ military.

The more likely outcome is that nothing changes. Even with a victory at Manzikert his opposition in Constantinople pulls a coup for the throne anyway and the same disastrous civil war follows, allowing a flow of turkoman raids in Anatolia and general destabilization that leads in the collapse of Anatolia holdings.

Worth to mention that a victory at Manzikert gave no assurance at a stop of Turkish raids in imperial holdings, considering the Seljuk Sultans had little real control over the nomads

[Sher Khan]

I believe they did both, pushing back the Fatimids all the way to the Sinai while also fighting the Byzantines in Anatolia.

Thing is, the nomad tribes the Seljuks brought with them for fast assembling manpower reserves could settle only Northern Syria and Anatolia, and they didn't penetrate south any further due to a lack of grazing fields for their horses and other animals.

The above is the reason why nomads began to stream into Anatolia, either by their own initiative or by Seljuk policy, until the Byzantine response. It was then that the Seljuk emperor, to answer the call by the incoming nomads for help, turned north from his campaign against Egypt, especially when he couldn't reach a truce with the Byzantines.