during his reign, Basil II planned to campaing in the Levant all the way south to capture Jerusalem. let's say he manages to do that, and conquer much of the rest the Levant too, and hold it against the Fatimids, Abbaids, Emirs of Aleppo, and so forth.
would this be a good position to launch an invasion / reconquest of Egypt? Basil could raise a fleet and a massive army and attack across the Sinai and through a naval assault. the Fatimids were beginning to decline in the early 11th century I think, so might the Byzantines be able to successfully retake Egypt from the Fatimids and restore it as part of the Empire? or is it ASB by this point?
As others have pointed out, a Byzantine reconquest of Egypt is very unlikely at this point, even in a best case scenario.
A Byzantine conquest of the Levant should be possible in a best-case scenario (i.e. Basil's successor being a militairy genius, along with the neighbouring Muslim nations having a severe bout of bad luck and the rise of the Seljuks being butterflied away), but even then, a Byzantine conquest of Egypt would be unrealistic.
Sure, the Byzantines could severely weaken the Fatimids, and they might even vassalize them.
But a direct conquest? - no.
The Makurians could (and propably would) take advantage of the decline of the Fatimids by conquering parts of Upper Egypt.
And in a best-case scenario, the Makurians could conquer most or all of Egypt. Again, this is not a likely scenario - but a Makurian conquest of Egypt under these circumstances would certainly be a lot more likely than a Byzantine conquest of Egypt.
Unlike Byzantium, the Makurians didn't have major concerns elsewhere, and the Makurians were a lot more tolerant towards Muslims than the Byzantines usually were.
And Makuria was still going strong during the 11th century, and a Makurian conquest of Egyptian territories is not unprecedented; during the early 960's (shortly before the Fatimid invasion), they managed to conquer as far north as Akhmim.
And archeological evidence from Edfu suggests that, in spite of the Fatimid invasion, the Makurians managed to hold on to at least a good part of these territories for decades.
However, it appears that there is not enough evidence to determine exactly
how far Makurian rule extended north, and how long Makurian rule lasted in Upper Egypt. (the Makurians might still have been in control of Edfu and nearby cities like Luxor, Qus and Qift in 1025 - but to my knowledge, there is not enough evidence to conclusively prove or disprove this)
How about the Romans kick out the Arabs and Egypt rebels and rules itself ? An independent Christian Egypt in this period would be very interesting !
Best Regards
Grey Wolf
I agree with Abdul - it's really too late for an independant Christian Egypt at this point.
At best, the Makurians might conquer Egypt (which will only happen if the Muslims have the kind of bad luck the Byzantines had when they lost Anatolia to the Seljuks), but that's about it.
An independant Coptic Egypt should be doable in the 8th and early 9th centuries, when there were still major Coptic rebellions.
I'd say the latest realistic POD for an independant Coptic Egypt would be making sure that Ma'mun either horribly screws up early during his reign (which would be unlikely, as he proved himself to be a very capable ruler IOTL), or never becomes Caliph in the first place.
There were revolts throughout Egypt during Ma'mun's reign, and at some point, he even personally led his army to Egypt in order to crush the revolts and restore order there.
If a very weak and incapable Caliph would have ruled during this period and/or if the Abbasids would have been too caught up in a civil war to respond properly to the revolts in Egypt, then the revolts could become so serious that the Muslims could very well lose most of Egypt, at least temporarily.
And in this scenario too, a Makurian conquest of Egypt is not unlikely. (in fact, I'd argue that this is one of the most plausible scenario's for a Makurian conquest of Egypt)