In looking up the Aabasids - Arabs in the area of Iraq around 750 A.D. - it is often mentioned that the Aabadids made great achievements during their Caliphate - 7500-1258AD. Actually, the Aabasid Arabs did not bring any such achievements with them, and most of what is called “their” achievments they got from the Egyptians, Assyrians and Persians who they conquered.
The Abasids were conquered by the Mongols and Mongol rule was followed between tbe 13th and 17th cenutries with rule by various groups until the Ottoman Empire took over in 1639, which lasted till its formal end in 1922 following the Ottoman’s defeat in WWI (they erred in siding with Germany). But what the Aabasids’ created in Islamic literature never got a period of deep internal analysis and questioning, The likely reason was very early on in Islam the idea of a separation of Church and state was unthinkable - the state was the head of the church and the church was an institution of the state. When religious orthodo=xy and the state are joined, there is seldom religous questioning.
IIRC, I read where Mohammad was a ruler and conqueror, and made up the religion in order to unify the various tribes that he conquered.
I may have misunderstood that though - and perhaps it was the Aabasids that used it as a unification tool.
From Wiki - Mohammad lived from 570 to 632 A.D. Receiving the Quran verbally from an angel during the period 610 to 632. (Perhaps Moe was a distant relation to Joe? Joseph Smith). It was written down and collected in one book in about 634?? (Maybe the 650’s).