The Hanbali School of law was founded by Abu Abdullah Ahmad bin Muhammad bin Hanbal bin Hilal al-Shaybani who was born in Baghdad from Arab parentage on the 20th of Rabi’ al-Awwal 164 AH (780 CE). His mother came to Baghdad from Merv whilst she was pregnant with him.  His father was a soldier posted in Basra and died whilst Imam Ahmad was at a young age. Imam Ahmad  was a very intelligent child, keenly interested in furthering his Islamic education. He began learning fiqh with Qadi Abu Yusuf and after becoming proficient in the Hanafi School, he began to study hadith under some of the greatest hadith scholars of Baghdad such as Hushaym bin Bashir al-Wasiti. At the age of sixteen he began studying hadith and it is said that he learnt almost a million hadith by memory. After studying in Baghdad, he went on to study in Mecca, Medina, Yemen, and Syria.
He studied fiqh under Imam al-Shafi’i in Mecca and Baghdad. Ibn Hanbal was extremely devoted to traditional views and was opposed to innovations in Islamic law. The strength of his views was tested under the caliphs al-Ma’mun and al-Mu’tasim. During the mihnah period, a kind of “inquisition court” was created to deal with people who would not profess certain doctrines that the Abbasid caliphs thought were correct. These doctrines were from the Mutazilite school of thought, and held that the speech of Allah was created and not eternal. Ibn Hanbal was arrested and brought in chains before the court, and suffered a great deal. He patiently submitted to corporal punishment and imprisonment for a period of two years, and resolutely refused to abjure his beliefs. Al-Ma’mun reportedly had Ibn Hanbal flogged.
Imam Ahmad once said, “The best of my days is when I awaken and find my cupboards bare. For that is a day my reliance on Allah is complete.”
From his works are; Al-Musnad (a compendium of approximately 28,000 hadith), Al-Nasikh wa al-Mansukh, Al-Zuhd, Al-Sunnah, and others.
After a brief illness he took his last breath on Friday, the 12th of Rabi’ al-Awwal 241 AH (855 CE). His funeral procession was perhaps the largest in the history of Arabia; 800,000 people attended the funeral.
The Hanbali School has historically and in contemporary times always had the least number of followers out of the four legal schools.
The Hanbali School has most of its adherents in Saudi Arabia and Qatar with some followers in Egypt, Syria, and Palestine.