Abu al-Qasim al-Husayn ibn Ruh al-Nawbakhti

Abu al-Qasim al-Husayn ibn Ruh Nawbakhti (, "", died 937 or 938 AD) was the third of the Four Deputies appointed by the twelfth Imam of Twelver Shias, Hujjat-Allah al-Mahdi during the Minor Occultation. He was a native of Qum who migrated to Baghdad during the time of Uthman ibn Sa'id al-Asadi, the first deputy. Al‑Nawbakhti was a companion of the second deputy Abu Jafar Muhammad ibn Uthman and became his agent for several years. After the death of al-Nawbakhti, Abul Hasan Ali ibn Muhammad al-Samarri was appointed as the fourth deputy of Hujjat-Allah al-Mahdi.
Biography.
The birth date of Husayn ibn Ruh al-Nawbakhti is unknown. He was a native of Qum (modern-day Iran), who migrated to Baghdad, Iraq, during the time of the first deputy Uthman ibn Sa'id al-Asadi. Husayn ibn Ruh al-Nawbakhti was a member of the al-Nawbakhti family who had a high position among Banu Abbas.
Before his deputyship.
During the Imamah of Hasan al-Askari, the eleventh Imam of Shias, Abu al-Qasim Husayn ibn Ruh al-Nawbakhti was one of his companions. He was also a companion and supporter of Abu Jafar Muhammad ibn Uthman, the second deputy of Hujjat-Allah al-Mahdi, his agent and the channel of communication between the Imam and his Shias.
Selection.
Under the direction of Imam al-Mahdi, Husayn ibn Ruh was appointed as the third special deputy by Muhammad ibn Uthman.
About three years before Muhammad ibn Uthman's death, to prepare the Shia community to accept Husayn ibn Ruh as the third deputy, Ibn Uthman began directing some of the Shias who were bringing the Zakat and Khums for Hujjat-Allah al-Mahdi to Husayn ibn Rauh. When he became seriously ill, a group of Shia elite went to see him and about the next deputy; he replied; "Husayn bin Ruh is my successor and the trusted deputy of the Master of the Age. Refer to him in your affairs. I have been commanded by the Imam to designate Husayn bin Ruh in the position of deputyship." When Muhammad ibn Uthman was about to die, he introduced Husayn ibn Ruh as his successor.
The first Tawqee from Hujjat-Allah al-Mahdi.
After the selection of al-Nawbakhti as the third deputy of final Imam of Shia, the first Tawqee, the letters that were signed by the Twelve Imams, from Hujjat-Allah al-Mahdi received him on Sunday, 917 AD (6th of Shawwal, 305 AH). The Tawqee said: "We know (Husayn ibn Ruh), may Allah confer all His Goodness and Pleasure on him and bestow His Bounties on him. We are aware of his letter, which is the cause of our reliance and certainty (upon him). We deem him meritorious, which makes him happy. May Allah increase His Favors and Goodness on him."
Death.
Husayn ibn Ruh was the deputy of Imam al-Mahdi amongst Shias for about 21 years until his death in 937–938 AD (18 Sha'ban 326 A.H). His body was buried in Baghdad.