Mezue ahịrịokwu na-esonụ: Mgbe ọnwụ nke Harun al-Rashid na 809, ụmụ nwoke abụọ nke Harun
bidoro ịlụ ọgụ maka ịchị alaeze Abbasid. Otu nwa nwoke, bụ́ Al-Amin, nwere nne bụ́ onye Arab, n'ihi ya kwa, ndị Arab kwadoro ya, ebe nwanne ya nwoke nke ọ mụrụ site n'ọkpara, bụ́ Al-Ma'mun, nwere nne bụ́ onye Peasia, Peasia kwadokwara ya. Mgbe o merisịrị nwanne ya nwoke, al-Ma'mun chere ọtụtụ nnupụisi ihu site n'aka ndị na-eso ụzọ ezinụlọ Muhammad n'ọtụtụ ebe.