The four imams

Kufa, the garrison city on the Euphrates, had been home to 'Abd Allah ibn Mas'ud RA, sent by 'Umar RA to teach its people, and to many other Companions. Their learning passed to 'Alqamah, to Ibrahim al-Nakha'i and then to Hammad ibn Abi Sulayman.

Al-Nu'man ibn Thabit, known as Abu Hanifa, was a silk merchant who sat in Hammad's circle for about eighteen years and then took his place as its teacher. Rather than giving rulings alone, he discussed each question with his students, testing their reasoning against the Quran, the Sunnah and the sayings of the Companions, and working through cases that had not yet happened. He refused the post of judge when the rulers offered it. His students Abu Yusuf and al-Shaybani recorded his method, and it became the Hanafi school. Watch the lines run from his teachers to his students.

Madinah was the city of the Prophet ﷺ and of the generations who had lived beside him. Malik ibn Anas was born there in about 711 and rarely left it except for the Hajj. He studied with Rabi'ah, with Nafi', the freed slave of Ibn 'Umar, with al-Zuhri and with Ja'far al-Sadiq, and began teaching in the Prophet's Mosque.

He was known for his reverence for hadith: he would bathe and put on his best clothes before teaching it, and out of respect for the ground where the Prophet ﷺ is buried he would not ride in Madinah. His Muwatta', 'the well-trodden path', brings together hadith and the practice ('amal) of the people of Madinah, which he saw as a living Sunnah. Students came from as far as al-Andalus and Khurasan to hear it.

In 767 Abu Hanifa died in Baghdad, by many accounts in prison for refusing the caliph al-Mansur's command to become a judge, and great crowds prayed over him. In the same year, in Gaza on the coast of Palestine, a boy named Muhammad ibn Idris al-Shafi'i was born to a poor family of Quraysh.

His father died when he was small, and his mother took him to Makkah, where his family came from. He memorised the Quran as a young child and the Muwatta' while still a boy, and spent years with the Bedouin tribe of Hudhayl, learning the purest Arabic, its poetry, and archery. His teachers in Makkah, among them Muslim ibn Khalid al-Zanji, allowed him to give fatwa while he was still young.

At about twenty al-Shafi'i travelled to Madinah to study with Malik, reading the Muwatta' to him from memory, and he stayed until Malik's death in 795. He later took a post in Yemen, was accused of supporting a rebellion, and was brought to Baghdad in chains; al-Shaybani, Abu Hanifa's student, is said to have spoken for him.

In Baghdad he studied the Hanafi books with al-Shaybani and debated with him. Having learned both the tradition of Madinah and the reasoning of Iraq, he set out to show how law should be drawn from its sources: the Quran, the Sunnah, consensus and analogy. His al-Risalah became the first book on the principles of jurisprudence (usul al-fiqh).

Ahmad ibn Hanbal was born in Baghdad in 780 and lost his father as a child. From his teens he gave himself to hadith, travelling to Kufa, Basra, the Hijaz, Syria and Yemen, where he walked to study with 'Abd al-Razzaq in San'a.

He met al-Shafi'i in Baghdad and studied fiqh and its principles with him, while al-Shafi'i in turn relied on him for hadith. Ahmad lived simply and refused gifts from rulers. He gathered some thirty thousand narrations into his Musnad, arranged by the Companion who narrated each one. Among those who learned from him were al-Bukhari and Abu Dawud, and his answers to questions, collected by his sons and students, became the Hanbali school.

In 814 al-Shafi'i moved to Egypt and settled in Fustat, the old capital beside the Nile, where Malik's students had spread his teaching. In his last six years there he revised much of what he had taught in Iraq. Scholars distinguish his 'old' opinions from Baghdad from his 'new' ones from Egypt, and his followers generally keep to the new.

His students recorded his teaching. Al-Rabi' al-Muradi transmitted al-Umm, the great collection of his works, and al-Muzani wrote the Mukhtasar, the summary on which the school was built. Al-Shafi'i died in 820, aged about fifty-four, and was buried at the foot of the Muqattam hills, where Salah al-Din later built a madrasa beside his tomb.

The caliph al-Ma'mun adopted the Mu'tazili view that the Quran was created, rather than the eternal speech of Allah, and in 833 ordered judges and scholars to affirm it. Most gave way under pressure. Ahmad ibn Hanbal refused, saying he would accept only what was in the Book of Allah or the Sunnah of His Messenger.

He was taken in chains and imprisoned, and under the caliph al-Mu'tasim he was flogged until he lost consciousness, but he would not change his answer. Around 848 the caliph al-Mutawakkil brought the inquisition to an end. When Ahmad died in Baghdad in 855, vast crowds followed his funeral. His steadfastness made him a symbol of the community's loyalty to the texts.

The map now shows only scholars of the Maliki school, each at the place where they rest. Students who heard the Muwatta' from Malik carried it west. In Qayrawan, Sahnun gathered the answers of Ibn al-Qasim, Malik's Egyptian student, into the Mudawwanah, which became the school's great reference.

From Qayrawan and Cordoba the school became the law of North Africa and al-Andalus. Ibn 'Abd al-Barr, Qadi 'Iyad and al-Shatibi wrote within it, and Ibn Abi Zayd's Risalah became the first book of countless students. Carried across the Sahara by traders and scholars, it is still the main school of North and West Africa.

Now the map shows the Shafi'i scholars. From Fustat the school spread to Baghdad, Khurasan and Syria. Its great names include al-Juwayni and al-Ghazali of Nishapur and Tus, al-Nawawi of Damascus, and Ibn Hajar al-'Asqalani and al-Suyuti of Cairo.

It travelled further still with traders across the Indian Ocean, to Yemen and Hadramawt, the coast of East Africa, and Southeast Asia. The sultans of Pasai followed it, and in Aceh, Banjar and Patani scholars such as al-Singkili, Arshad al-Banjari and Dawud al-Fatani wrote its books in Malay. Today most Muslims of Malaysia, Indonesia, Brunei and southern Thailand follow it.

Finally, the Hanafi scholars. Abu Yusuf, chief judge under Harun al-Rashid, made the school the law of the Abbasid courts. It spread east through Khurasan and Transoxiana, where al-Maturidi gave it its theology and al-Marghinani wrote the Hidayah, and it was carried by the Seljuks, the Ottomans and the Mughals across Anatolia, the Balkans and India.

Today it is the most widely followed of the schools, from Turkey to Central and South Asia. The fourth school, the Hanbali, the smallest, flourished among the scholars of Baghdad and Damascus, among them Ibn Qudamah and Ibn Taymiyyah, and is followed today mainly in the Arabian Peninsula. The four schools have long recognised one another as sound paths within Sunni Islam.