There are Byzantine Armenian dimensions to this story that I suspect not many people know. Cyrill and Methodius were taught by Leo the Philosopher and Photios, in the University established by Bardas, all Greek-Armenians who clearly knew the transformative effect of having your own writing system (it saved Armenians from assimilation just a few centuries prior to these events). It took Hellenic culture of Byzantine period and Armenian experience to give birth to the first Slavic writing of Moravia and Bulgaria, and later most of Eastern Europe.
Incidentally, the first writing system (Glagolithic) didn't stick nearly as well as the subsequent iteration (Cyrillic) because the latter was so much closer to Greek, and every educated person already knew how to read/write Greek so it was a much easier sell. Regardless, this invention and its promotion was very much a planned and well-understood Byzantine project.
> Thus Bardas founded the Magnaura School with seats for philosophy, grammar, astronomy and mathematics, supported scholars like Leo the Mathematician and promoted the missionary activities of Cyril and Methodius to Greater Moravia.
Did you mean the second paragraph as Cyrillic being closer to Greek? That makes sense but I was confused at first and thought you meant Glagolitic being closer, which makes very little sense.
Incidentally, the first writing system (Glagolithic) didn't stick nearly as well as the subsequent iteration (Cyrillic) because the latter was so much closer to Greek, and every educated person already knew how to read/write Greek so it was a much easier sell. Regardless, this invention and its promotion was very much a planned and well-understood Byzantine project.
> Thus Bardas founded the Magnaura School with seats for philosophy, grammar, astronomy and mathematics, supported scholars like Leo the Mathematician and promoted the missionary activities of Cyril and Methodius to Greater Moravia.
https://en.wikipedia.org/wiki/Bardas https://en.wikipedia.org/wiki/Leo_the_Mathematician https://en.wikipedia.org/wiki/John_VII_of_Constantinople https://en.wikipedia.org/wiki/Photios_I_of_Constantinople
(these further cite primary sources)