The purpose of this thesis is to study the process of the development of the Naqshbandiya-Mujaddidiya in the Ferghana Valley at the period of the khanate of Khoqand. It is well known that during the later history of the khanate the so-called Miyan or Sahib(-zada) shaykhs, who were the descendants of the founder of this branch, Khwaja Ahmad Sirhindi (d. 1624), established close relations with the rulers of the khanate and occupied higher positions in the government. However, only very fragmentary information about the development of the Naqshbandiya-Mujaddidiya in the Ferghana Valley has come down to us. In this thesis six historical documents called ijdzat-ndmas (the licenses issued by masters to their disciples), which were recently discovered in local private possessions in the Ferghana Valley, are introduced and examined in order to clarify the master-disciple relationship and, by comparing them with other historical sources, to investigate the process of the arrival of the Naqshbandiya-Mujaddidiya to the Ferghana Valley. The doctrine of the Naqshbandiya-Mujaddidiya spread over the Ferghana Valley mainly in the first half of the nineteenth century; the pivotal role in this process belonged to Khalifa Muhammad Husayn (d. 1833/34) (one of the grand-disciples of Musa-khan Dahbidi, who contributed to introduce this branch to the amirate of Bukhara) and his disciple 'Abd al-'Aziz Majdhub Namangani.