In the 860's the Byzantine Empire began to recover from Arab incursions so that by 872 the military balance with the Abbasid Caliphate had been permanently altered in the empire's favor.
There's still a lot more of the text and so that first fragment a part, but I immediately begin to form an opinion about this part with respect to an imagined or supposed whole.
However, the public school, as an imagined functional entity, has been confronting the separation of and conflicts between institutional structure and technological structure since the very beginning.