His Shaykh is from the eastern side of Turkey, from an area in the region of Georgia and Shām. With the counsel of his Shaykh, he left the bordering region and went to the capital city, Istanbul. There is an area in Istanbul called Fātih, attributed to Sultān Muhammad Fātih. An area of Fātih is Ismā'īl Āghā, counted among the elite areas. The Masjid of Shaykh ul Islām Ismā'īl Āghā Āfandī is located here. He was the Shaykh ul Islām in the time of the 'Uthmānī Khilāfat.
The Khulafā' of Shaykh Mahmūd say that he led the Salāh in this Masjid for thirty years. For the first eighteen years, no one would come to the Masjid. Shaykh Mahmūd would go door to door and tell the people of the locality that he is always in the Masjid. If someone went to work, he would tell him, "Remember me." His attendant remained with him through every difficulty. After eighteen years, making the Dhikr of Allāh, the ice melted, the rigidity gave in, the focus and Du'ā' of the Shaykh started showing and Salāh with Jamā'ah in the Masjid began. The condition in that locality today is such that there is no household without Salāh and no person that does not have the Sunnah appearance of the beard and turban. The women have all adopted the full Shar'ī Hijāb.
Some of the contemporaries of Shaykh Mahmūd are referred to as Mujaddid. The reason for this is that they filled the Masājid and Khānqahs in a number of localities. Masājid in which Adhān was abandoned, today, these Masājid are full even before Jumu’ah Adhān. After Salāh, these Masājid resound with Dhikr. However, the work of Shaykh Mahmūd is even more than this. Description of it is a means of very interesting reading, Inshā Allāh.
Excerpt taken from "The Turks, From Unenlightened to Enlightened," by Mufti Abu Lubaba HA.