Al- Imam Al Adham Abu Hanifa's RA , name was Numan. His father's name was Thabit. His grandfather's name was Numan, too. He was the first of the four great imams of the Ahl as-Sunnah.

Imam Abu Hanifa , was a descendant of a Persian notable, he was born in Kufa, Iraq in 80 AH (698 CE). He learned Fiqh (Islamic Jurisprudence) with the help of Hammad ibn Abi Sulaiman. He enjoyed the companionship of many notables of the Tabiin, and of Imam Jafar as-Sadiq AS. He memorized innumerable Hadiths. He was brought up so as to become a great judge, but he became an imam Al-madhhab. He had a superior and amazingly keen intellect. In fiqh, he attained an unequalled grade in a short time. He then became very popular all over the world.

Imam Abu Hanifa joined his father's business, where he showed scrupulous honesty and fairness. His agent in another country once sold some silk cloth on his behalf but forgot to point out a slight defect to the customers. When Abu Hanifa learnt of this, he was greatly distressed because he had no means of returning the money to the customers. So he immediately ordered the entire proceeds of the sale of the consignment of silk to be distributed to the poor.

Abu Hanifa's interest in Islamic jurisprudence was sparked perhaps by chance. While running an errand for his mother, he happened to pass the home of Sha'bi, one of Kufa's most well-known scholars. Sha'bi, mistaking him for a student, asked him whose classes he attended. When Abu Hanifa responded that he did not attend any classes, Sha'bi said, "I see signs of intelligence in you. You should sit in the company of learned men." Taking Sha'bi's advice, Abu Hanifa embarked on a prolific quest for knowledge that would in due course have a profound impact on the history of Islam. Of the most prominent of Abu Hanifa's teachers was Imam Jafar Sadiq AS, who is regarded by many Islamic scholars as the root of most of Islamic jurisprudence, with a massive influence on Hanafi, Maliki and Shia schools of thought extending well into mainstream Hanbali and Shafi'i thought. Abu Hanifa is quoted by many souces as having said "If it was not for those two years [I spent with Ja'afar as-Sadiq] Numan [Abu Hanifah] would have perished" : law laahu sanataan la halaka'n nu'man.

Imam Abu Hanifa is also said to have studied Fiqh from Hammad ibn Abi Sulayman and was eventually his successer in teaching Fiqh. Hammad ibn Abi Sulayman himself was the successor to Ibrahim an-Nakha'i, who was the successor to his uncle 'Alqamah ibn Qays an-Nakha'i, a student of 'Abdullah ibn Mas'ud, a companion of the Prophet Muhammad.

Islamic Jurisprudence (fiqh) was systematically studied by his students under his guidance. A number of his devoted and highly intelligent students worked under him for thirty years, and it is their labor which produced the Hanifi school of Islamic jurisprudence.

Imam Abu Hanifa was probably the most broad-minded of the four great Sunni Imams of fiqh. The Hanafi fiqh is thus the most flexible and adaptable. He saw Islamic law as an organic growth in which changes would be necessary from time to time as society changed. He advocated the use of reason based on the Qur'an and the Sunnah in the consideration of religious questions.

Yazid ibn 'Amr, Governor of Iraq during the time of Marwan ibn Muhammad, the fourteenth and last Umayyad Khalifah, asked Abu Hanifa to become a judge for the law-court of Kufa. But, since he had he refused his offer, for he wanted to devote his time and effort serving Islam, and had not interest in worldly pleasures. He was afraid of not being able to safeguard human rights because of human weaknesses. With a command from Yazid, he was given a whipping, hundred and ten blows to the head. His blessed face and head swelled. The next day, Yazid took the Imam out and oppressed him by repeating his offer. The Imam said, "Let me consult," and obtained permission to leave. He left to Mecca and remained there for five or six years.

The 'Abbasid Khalifah Abu Jafar Mansur offered Imam Abu Hanifa to be the chief of the Supreme Court of Appeal in 150 A.H. [767 A.D.]. Again the Imam refused, and was put into jail. He was subjected to whipping, ten blows more every following day. When the number of whipping reached one hundred, he attained martyrdom. So many people attended his funeral that the funeral service was repeated six times before the Imam was actually buried. Abu Sad Muhammad ibn Mansur al-Harizmi, the third Saljuqi Sultan and the son of Sultan Alparslan, had a wonderful dome built over his grave. Afterwards, Ottoman emperors embellished and had his tomb restored several times.

Imam Abu Hanifa was the first to compile and classify the Fiqh science; he collected information for each branch of knowledge. He wrote the books Fara'id and Shurut (Obligations and Conditions). There are a lot of books describing his wide knowledge on fiqh, and his amazing superiority in piety, God consciousness, mildness and righteousness.

The Hanafi Madhhab (approach) spread far and wide during the time of the Ottoman Empire. It almost became the official Islamic approach of the State. Today, more than half of the Muslims all over the world follow this approach.

References:

http://www.islamonline.com/cgi-bin/news_service/profile_story.asp?service_id=855

http://en.wikipedia.org/wiki/Abu_Hanifa_an-Nu%27man