That was true in medieval times. From the start of the early modern (e.g. Henry VIII) the Church of England used English for services.
The prestige also accrued because it was the language of the educated in Europe for a long time.
The prestige also accrued because it was the language of the educated in Europe for a long time.
I was going to answer with just "the church" but the OP specifically asked about academia.
A good analogy is French being the language of the elite in Britain, well after the Normans got merged into the general population.
Well not in the west where the elite was replaced by uneducated barbarians for several centuries and it took quite a while for the church to teach them how to read and write again.