Qadi Abu Yusuf was a descendent of the Ansar and Sahaba Hadrat Sa'd b. Sibat. Born in Kufah in 113 or 117 H and passed away on the 5th of Rabi' al-Awwal 182 H. Muhammad b. al-Hasan al-Shaibani was born in 135 H and
passed away in 189 H. He attended for about 2 yrs the lectures of Imam Abu Hanifah (RA), and upon the latter's death, he completed his education under Abu Yusuf. He also studied for 3 yrs the Muwatta of Imam Malik (RA) under the great Imam himself, in Medina.

Qadi Abu Yusuf As long as Imam Abu Hanifah (RA) lived he regularly attended his court. Imam Abu Hanifah acknowledge his mastery in Fiqh. Returning once from a visit to Abu Yusuf during the latter's sickness, Abu Hanifah (RA) said to his companions: "If, Allah forbid, this man (Abu Yusuf) dies, the world will lose one of its great scholars."

Abu Yusuf attended the lectures of many other doctors. He heard Traditions from A'mash, Hisham b. 'Urwah, Sulaiman Taimi, Abu Ishaq Shaibani, Yahya b. Sa'id al-Ansari and others, learned maghazi (military history) and siyar (biography) from Muhammad b. Ishaq and knowledge of Fiqh from Muhammad b. Abi Laila. Allah endowed him with so much intelligence and such a good memory that he learned all these disciplines simultaneously! Other Imams in other sciences ackowledged his quick intelligence and penertration.

Although he is known mostly in Fiqh, he was unrivalled in other sciences.The historian Ibn Khallikan quotes Hilal b. Yahya as having said: "Abu Yusuf was a hafiz of tafsir (exegesis), maghazi and ayyam al-'Arab
(history of Arabia), Fiqh was one of his minor accomplishments."

1. Abu Yusuf was ranked so high in Hadith so as to be counted huffaz in it, the famous and strict muhhadith Dhahabi included an account of Abu Yusuf in his Tadhkirat al-Huffaz.

2. Ahmad Hanbal (RA)said "When I was first attracted to Hadith, I went to Abu Yusuf."

3. Muzni, a famous disciple of Shafi (RA) used to say: "Abu Yusuf follows more Hadith than anybody else. 'Abd al-Barr, a well-known Muhaddith, writes that Abu Yusuf used to visit different Muhaddithin and at one sitting learn 50 to 60 Traditions, all of which he would retain in his memory!

4. A'mash the famous muhaddith having consulted Abu Yusuf on a question, said on hearing his reply: "Have you any authority for this?". "Yes", replied Abu Yusuf, and he reminded A'mash of a Tradition which the latter had narrated to him on a certain occasion. "Ya'qub", said A'mash, "I first heard this Tradition when your parents had yet not got married, but I have understood its meaning only today" (Ibn Khallikan, Ta'rikh, note on Abu Yusuf).

Imam Muhammad Shaibani
The great Imam, Imam Shafi (RA) said: "Whenever Imam Muhammad expounded a point of law, it seemed as if the revealing Angel had descended upon him."

"I acquired from Imam Muhammad a camel-load of learning" Ibn Hajar quotes Imam Shafi as having said: "....I used to visit him (Muhammad b. Hasan). I told myself that he was of high rank in Fiqh too.
Therefore, I made it a point to attend upon him, and I used to take down his lectures."

[note: In his early days Ibn Tayimmah denied that Shafi was a pupil of Imam Muhammad, but hundreds of historical books and rijal bear witness that Imam Shafi associated with Imam Muhammad]

On somebody asking the great Imam, Imam Ahmad Hanbal where he had learnt all the subtle points of law he used to make, he replied, "From the books of Muhammad b. Hasan." (Tahdhib al- Asma' wa'l-Lughat byImam Nawawi).

Again, similar to his teachers, most of his fame rests with his work in Fiqh but he had the rank of Mujtahis in exegesis, Tradition and literature also. Imam Shafi (RA) is reported to have said: I have not come across a man
more learned in the Quran than Imam Muhammad." (Al- Jawahir al- Mudiyyah). His complete grasp on literature and Arabic linguistics is seen questions of fiqh based upon grammatical points in his Jami' Kabir. Jami Kabir is a
voluminous work where the dicta of Imam Abu Hanifah (RA), Imam Abu Yusuf and Imam Zufar are quoted with the questions and arguments. Later Hanafi scholars used this book as the basis of the methodological reasoning
employed by the Hanafi school.

Shaykh al-Kadi, a latter day scholar said in a talk (Fiqh and Fuqaha) that Fiqh is the fruition of all the other Islamic sciences such as Hadith, Exegesis, Grammer, History and so forth. These two great Imams were recognized Mujtahids in all the sciences making them Mujtahid Mutalaqs of the Mathab. The same holds true for the other
Mathabs. Many scholars consider some of Imam Shafi students to be Mujtahid Mutlaqs also. The genius of Imam Abu Hanifah (RA) in operationalizing the Quran and Sunnah was nurtured and matured under the genius of his
students.

As time went by, scholars who were masters in the Hanafi Mathab methodology and its basis became the Mathabs custodians, such as Imam Abideen. We lay Muslims are indebted to these great Scholars for allowing creating and maintaining a vehicle for us to traverse and protect us on the "Straight Path" to our Lord and Creator, based on the teachings of Allah's beloved, our Prophet and leader in this world and the next, Muhammad, Peace and choisest blessings be upon Him and the Ahlul Bait.

This information has been obtained and adapted from the english translation of "Sirat-i-Numan" by Allamah Shibli Nu'mani translated by M. Hadi Hussain.