Church Names in Brennenburg's Rooms

[Spelos]

Well,
I would say that castles (in general) were actually a little bit more than just fortification. It is obvious that people lived there for long periods of time. That's why there are your typical kitchens and wine cellars.

In that time period, Christianity is very prominent especially among high social status people. Usually, the king or the ruler were often thought as very close to the God.

It would make sense for Christian people, living in a castle like Brennenburg, to have a place where they could prey.

You, however, have a point about those places not looking really like the places they're called after. In that sense, Alexander himself, has to refer to those places somehow. He is out of this world and therefore, his terminology would not make sense to anyone and so he might have called the places something they kinda look like and other people can understand.

But then again... I'm no expert.