(G&K) Religion q - I don't really understand why?

Something (fairly incidental) happened in current game that I didn't think was possible, and I wondered if someone can shed light? To set the scene...

early part of game:
Harun is near me, founds Islam; sometime later I was at war with him and captured all his cities but Damascus. Over time Damascus converted to my religion (from no religion), as did all his other original cities inc Mecca (but Mecca being the holy city did not convert fully).

mid game:
I go on to fight wars in succession. Harun never founds another city - caught up in some ongoing unresolved war with Spain (one of those 1U at a time AI specials that last for ever).

late game:
game is just about over. I notice an Arabian GP sneaking towards York, which a turn later tries to convert it. So I DOW, kill it and finish off Harun (who cares by now, the other Civs bar Rome hate me anyway) Before I did I noted that Damascus had 2 Islamic followers but was still majority "Church England".

Sorry, long-winded. The bit I didn't get was how come he could generate a GP for a different faith to the majority? I didn't think that was possible?

Thats correct, but its possible to obtain a GP if you capture it from Barbarians, and I think you can also capture it from other civilizations. Probably what happened was the prophet was captured and taken to an encampment, and arabia sent a warrior and destroyed the encampment taking the prophet with it, (despite being another religion to their own.)

Its pretty useless unless you want to spread someone elses religion, so I always just delete it.

No it was Islam - that's my point/question. He generated a GP for his founded religion when the only city he had had a majority of another religion and it wasn't the holy city. I haven't really studied religion but I didn't think that was possible

If he has one remaining city, even if it is not majority his religion, he can generate a GP of his religion (any GP a player generates will always be of his religion, wherever it spawns). Does not have to be generated in his holy city (which you owned at that point).

GP are always generated from the religion you founded , if you did found one , regardless of the current status of your religion in your cities. It s a rule.

It means you can be at zero followers on the map , you will still generate GP from your religion.

thanks for clearing that up