During his reign (1839-1861), the Ottoman Sultan Abdulmejid I granted a plot of land in the heart of present-day Beirut to Sheikh Omar ibn Muhammad al-Yafi, the Damascene leader of the Khalwati Sufi method group, for the purpose of establishing a mosque, a zawiya (Sufi lodge), a house, and a market in 1270 AH (1850 CE). Sheikh Omar entrusted the supervision of this project to his son, Sheikh Muhammad Abu al-Nasr al-Yafi. The market and zawiya bear the name of Sheikh Abu al-Nasr to this day. The mosque and zawiya were later replaced by the Muhammad al-Amin Mosque, which stands today overlooking Martyrs' Square in central Beirut.