Al-Hassan ibn 'Ali ibn Khalaf al-Barbahary (? -329)
Shaykh al-Hanabilah, al-Qudwah, al-Imam, Al-Faqih, az-Zahid. He was tough on people of innovation and sin, he refuted Abu al-Hassan al-Achari in his time.
The excellent Sharh as-Sunnah of Imam al-Barbahaaree (his Aqeedah and his Minhaj), with Tahqeeq and Tashkil to facilitate reading and learning !