Al-Ḥasan ibn ʻAlī al-Barbahārī (867-941 CE) was a Muslim theologian and populist[2] religious leader from Iraq.
He was a scholar and jurist who is famous for his role in suppressing S̲h̲īʿa missionaries and Mu'tazilism in the Abbasid Caliphate during his lifetime.
[8] He was very influential among the urban lower classes, and exploited popular grievances to foment what often turned into mob violence against religious minorities and supposed sinners.
[11] Under the influence of al-Barbahari and the popular pressure of his followers, the Caliphs Al-Muqtadir and Al-Qahir enforced Sunni "orthodoxy" (according to the Athari creed) as the state creed, exiling and imprisoning al-Barbahari's enemies and even burying renowned Muslim historian Muhammad ibn Jarir al-Tabari, considered a heretic by most Atharis at the time, in secret due to fears of mob violence were a funeral to be held at the public graveyard.
Like other Hanbalis', Barbahari strongly opposed bidʻah (religious innovation), defined as anything regarding worship that the first generation of Muslims (known as the Companions of the Prophet or Sahabah) "did not do".