Somehow the OP is under the impression that England doesn't care about those provinces. History suggests otherwise. With royal marriages all over Europe, clearly all those lands where known well enough by all of Europe.
The history goes a bit like this: Normans had a royal marriage (or more) with England in the 11th century. A Norman named Roger I conquered Sicily in the 11th century, kicking out the Arabs.
Clearly Sicily was known to England, who in turn were linked by royal marriages, offspring, etc to the Normans.
AE with England, whilst probably too high in the current beta patch definitely is acceptable.
Besides all of this, most of Western and Central Europe was catholic, they knew the history of Al Andalus and would be rather upset if muslims came back, this time with a vengeance of taking huge tracts of lands/lots of provinces in relatively short time. Of course you should have coalitions forming against you. In a way you can look at it as a sort of a preparation for a crusade. Should this AE vanish ? Maybe slower than with non christian nations. Unless they are religiously tolerant, they want nothing to do with the muslims.
Another viewpoint would be this: what if tomorrow IS/IS runs rampage and manages to siege and take over large parts of lands in Spain, Portugal, Italy, etc. Don't you think that every country in Europe, including USA, maybe Russia and many non European countries will form a coalition to counter the scourge and beat them back ? THAT is AE for you.
Edit: and if you come back every 10 years or so to take over more land/countries, do you really think AE should come down fast ? They will not trust you so why should their willingness to form coalitions against you stop ?
Someone else mentioned countries' fear for being next, that is exactly right.
Don't tell me if ISIS comes to Italy, takes it all in 20 years, you sit in Denmark and think, oh well, in 10 years it will all be fine again. But then 10 years later ISIS comes back to take over Switzerland, 10 years latedr half of Germany, etc... at one point they will be on your doorstep... as of what point will you say 'holy sh*t', I wished I had joined those coalitions all those years ago...?
Edit2: or worse, send your diplomat to see if they want to be your ally
