Wow, Mr Bibby #180. There was me believing that Islam was a religion practised by many nations and now I see that it is actually one country that has invaded, y'know, very much like the country called Christendom. Christendom burst out of the turn of the BCE/CE epoch and invaded Europe too. Once established you had to be the right type of Christian as well (see Catholic v Cathars; Catholic v Protestant etc. etc. etc.) - sound familiar (Sunni, Shi'a)?
Obviously, Bill Warner (or actually Bill French to give him his real name) is missing the USSR era. The new baddy is the country of Islam, it is the new bete noire.
https://en.wikipedia.org/wiki/Christianity_in_the_4th_century The maps are interesting.
