Since in the half of the second hijri century, a lot of Islamic law (fiqh) school were founded and they became institutions to be adopted most of Muslims. Undoubtedly, to be mentioned with the name of same madhab imams (leader) is not simple naming. İn the contemporary debates even if some argued that the madhab leader din not found this madhab schools and there is no difference between them and another fakihs, when examined classical period usul writing, according to this usul writings, the leaders of madhabs were practicing different activities. With al-Cuwayni, this subject was take into consideration in the matter whether the madhab of sahabe could be followed or not. According to al-Cuwayni, the madhab of founder İmam’s was different from madhab of sahabe’s. Therefore it should be followed the madhab of founder İmam’s. In the study based on classical usul writings, we took into consideration activities of madhab leaders. Considered in the usul writings, it can be argued that three different activities emerged. The most important one of activities is that leaders the madhabs founded an ijtihad usul by examining and considering ancient tradition. Second one is that, based on the first one, they acquired general judgment (ahkam). The last one is that they collected the fiqh based on this datas.
Founder Imam, Madhab, Abu Hanifa, Ljtihad Usul, Fiqh