A mixture of Shi'i dervishes and secular rebel leaders who seized western Khurasan amid the Ilkhanate's disintegration, ruling from Sabzevar with an unusual dual religious-secular structure and largely escaping Timur's later brutality by submitting peacefully.
Their last ruler, Khwaja 'Ali-yi Mu'ayyad, submitted to Timur in 1381, ending Sarbadar independence without the massacre Timur inflicted on more defiant states.
The standard dedicated English-language monograph on the Sarbadars, their formation, and dissolution under Timur.