830s in the Abbasid Caliphate

historical event

thumb|right|300px|Map of the Mihna and events associated with itThe Mihna () was a period of religious persecution instituted by the Abbasid caliph al-Ma'mun in 833 in which Sunni scholars were punished, imprisoned, or even killed unless they conformed to Mu'tazilite doctrine. The policy lasted for eighteen years (833–851) as it continued through the reigns of al-Ma'mun's immediate successors, al-Mu'tasim and al-Wathiq, and four years of al-Mutawakkil who reversed it in 851.

battle in Asia Minor between Byzantines and Abbasids (838 CE)

conflict (811–813) between the brothers al-Amin and al-Ma'mun over the succession to the throne of the Abbasid Caliphate; provincial turmoil continued until the 830s