It is not difficult to estimate that there have been thousands of Sufis who contributed to the transmission of Sufi (taṣawwuf) life and thought to the present day. Some of these were those who produced the thought, while a large portion were those who disseminated, transmitted, and interpreted it. It will be beneficial to touch upon a few of the dervishes who guided the Sufi world and brought new dimensions to it through fresh interpretations. Since some of these figures will be mentioned when introducing the classics or providing information about the Sufi paths (tariqa), their names will not be repeated here.
In the foundational phase of Sufi life, schools (ekols) emerged in different regions. These schools, by placing greater emphasis on certain subjects and focusing on them meticulously, trained individuals accordingly. Junayd al-Baghdadi listed the regions where Sufis lived in the early centuries and the topics they especially emphasized as follows: in Baghdad, ecstatic utterances (shaṭḥiyya) and worship; in Khurasan, the heart (qalb) and generosity; in Basra, asceticism (zuhd) and contentment; in Damascus, gentleness and submission; in the Hijaz, sabr (patient endurance) and turning to God (ināba).
Based on this observation, it would not be incorrect to speak of a Baghdad school and a Khurasan school in Sufism (taṣawwuf). Sometimes, regions have also been identified with certain names. Qushayri relates the following: There are three people in the world who have no fourth: Abu 'Uthman al-Hiri in Nishapur, Junayd in Baghdad, and Abu 'Abdullah ibn Jalla in Damascus.