And were the Egyptian converted to Shia ?
There could very well have been converts to the Shi'ism during the Fatimid period.
IIRC most Shi'ite communities in the Levant were formed during the Fatimid period, and the university of al-Azhar was originally a Shi'ite university, so there were most propably Shi'ites in Egypt as well during the Fatimid period.
However, Shi'ites have never been a majority in Egypt, and I don't think that they ever were a large minority either.
I think it was quite a bit more then that. They're about 12% today and they're supposed to have declined a lot.
They weren't as widespread as ill informed AHers would think in the search for something cool but they were definatly a very important large minority.
The rate at which Egypt was Islamized is a rather hotly debated subject, and scholarly opinions vary greatly on this.
And from what I've read, there are also quite a few gaps in the documentation on this, so we may never really know at what rate the Egyptian population was Islamized.
But the are nonetheless interesting clues and (occasionally conflicting) bits of evidence: there are scholars who claim, based mainly on fiscal sources, that about half the Egyptian population was Islamized during the first forty years of Muslim rule, and that the Copts were little more than 20% of the population of Egypt by the year 800.
But on the other hand, there are scholars who claim that the process of Islamization was much less rapid, and that Muslims did not become a majority in Egypt until the 10th century or even later.
I have also seen researchers who claim that the main wave of conversions to Islam in Egypt happened in the period between 900 and 1100, and that the Muslim population increased from about 25% in 900 to about 75% in 1100.
And there are still other researchers who claim that Muslims did not become a majority in Egypt until even later, such as in the 12th or even 13th century.
And there are some rather interesting clues that could indicate that the Coptic community remained fairly large in Egypt until at least the 12th century; in 985, al-Maqdisi, an Arab geographer, mentioned that there were many towns in Egypt where there were not enough Muslims to build a mosque for, and at the end of the 11th century, the number of bishoprics in Egypt remained stable at between 50 and 60 (for comparison: prior to the Muslim conquest, Egypt had just over 100 bishoprics, and IIRC the Coptic Church was suffering from several internal problems during this period, so it seems very likely to me that it was in no position to maintain an excess number of bishoprics).
Other noteworthy facts are that there was what is described as a Coptic cultural renaissance during the 12th and 13th century, and various original works as well as translations of older works into the Coptic language happened until the early 14th century.
The fact that Coptic culture still thrived during the 13th century could be a good indication that the Copts were still a large community (albeit propably a minority) in Egypt at this point.
Other factors that have to be kept in mind when debating the Islamisation of Egypt, are the fact that the process of Islamisation and Arabisation happened much faster in the Nile Delta, while Copts remained the majority in Upper Egypt for much longer (I've seen researchers claim that the Copts may have remained a majority in Upper Egypt until the 12th century, and maybe even afterwards).
The fact that the Nile Delta was Islamized much faster than Upper Egypt, was due to the fact that many of the Muslim Arabs who settled here gave up their nomadic lifestyle and started to practice agriculture. Because of this, these settlers adopted a lifestyle that was very similar to that of the local Copts, with as a result that there was much more contact between these sedentary Arabs and the local Copts than there was between the nomadic Arabs and the local Copts.
And these contacts between sedentary Arabs and Copts resulted in intermarriage and conversions.
And the Nile Delta was a more likely place for Arabs to settle, simply because it was closer, and there was the threat of the occasional Nubian raid or invasion in Upper Egypt.
Someone mentioned the possibility of a Muslim sultanate still in Egypt.
That would have been me.
I don't believe this is possible. A division between Upper and Lower Egypt was only possible in an earlier era. Military technology was too far along for such a division.
Oh, I don't doubt that the Crusaders had the militairy technology to conquer Upper Egypt - but the main issue here is: did they have the resources to do so?
Egypt has a much larger population and a much higher population density than any other territories in the Levant that the Crusaders controlled, and even the Crusaders in the Levant were almost constantly short of manpower.
And would the Crusaders really have the resources and manpower to conquer and control all of Egypt?
And if I have to be honest, I don't think they did.
However, I could be mistaken in that...