Great educators, unlike soldiers, don't just fade away. Something lives after them.
A case in point is Alcuin (732-804), a British scholar recruited by Charlemagne, who had united Europe and managed to get crowned "Holy Roman Emperor" (thus establishing the "divine right" of kings). Charlemagne, possibly illiterate himself, wanted all his subjects - sons of Lords and sons of serfs - to learn to read and write. He asked Alcuin to make it so. Alcuin created Abbey Schools everywhere - an idea that grew over the next few centuries into something new in the world: universities.
Then there is Bishop Robert Grosseteste of Oxford (1175-1253). The guy was a standard medieval religious dude, but he was as interested in science (as yet unnamed) as in theology. His experiments in optics led his best student, Roger Bacon, to advocated what he called "experimental physics."
The rest, as they say, is quantum mechanics, dark matter and dark energy, and whatever the hell is next.
(I left out Peter Abelard (1079-1142), probably the most revered teacher of the period, because he's too famous. (Recall the tragic story of his love affair with the brilliant Heloise: Think of a nunnery. Think of Heloise's uncle, a mistaken idea that Abelard had abandoned her, and an emasculation by goons hired by the uncle. Sorry to leave you out, Pete.)