Ahmad ibn Hanbal was born in Baghdad in 164 AH. In search of hadith he travelled through Iraq, the Hijaz, Yemen and Sham. His al-Musnad is one of the largest collections of hadith.
In the time of the Abbasid caliph al-Ma'mun, scholars were being compelled by the state to affirm that the Quran is a created thing. History calls this trial the Mihnah. Many scholars yielded under pressure; Imam Ahmad said: the Quran is the speech of Allah.
Under the next caliph, al-Mu'tasim, he was imprisoned and flogged. Still he did not change his position. At last the caliph al-Mutawakkil ended the policy. He died in Baghdad in 241 AH; biographers describe a vast crowd at his funeral.