It’s a good place to root it. Have a look at: https://en.wikipedia.org/wiki/Gemistus_Pletho and his connection to Byzantium for without him as well as the Eastern Orthodox monk that wanted him to come (who said “no” to Purgatory and the Latin Pope) and the otherwise failed Council of Florence, the Byzantine education would not likely have made it to the West before the fall of Byzantium, spawning the translations that spawned the schools that led to the Renaissance humanistic movement.
Quite an amazing chain of events. It’s unfortunate that Gemistus Pletho often doesn’t get the mention he deserves in our received cultural narrative.
The way our narrative tends to read, humanism appears to almost be a natural consequence, as if some kind of inevitable progress, a holdover from older 19th century narratives which had strange tales of ages Dark and Middle, some of which are still being taught today, improperly so.