Imam Ahmad ibn Hanbal is remembered for many things. He was an Imam in Fiqh, Hadith, and many other sciences. In fact, his madhhab is one of the four established madhhabs of Ahl as-Sunnah wal-Jama'ah. Yet, the one matter he is most remembered for... one of the most defining moments in the History of Ahl as-Sunnah wal-Jama'ah... is his stance in the time of the Mihnah (the Inquisition).

Imam 'Ali ibn al-Madini, the great teacher of Imam al-Bukhari said, "Truly, Allah supported this religion with Abu Bakr as-Siddiq the day of the apostasy (ar-Riddah), and He supported it with Ahmad ibn Hanbal the day of the Inquisition (al-Mihnah)."

Imam ash-Shafi'i said, "I left Baghdad and did not leave behind me anyone more virtuous, more learned, more knowledgeable than Ahmad ibn Hanbal."