The word "mazalim" is the plural of mazlima, which means iniquity, act of injustice, or wrong doing. In terms of Islamic judicial system, mazalim denotes a special type of court, where sessions for hearing cases of injustices are held or supervised by the supreme political authority, or by one of his close deputies or other high-ranking authority.
In the view of al-Mawardi (d. 1058), the institution of mazalim existed in the pre-Islamic Arab community and also under the Sassanid regime. Mawardi mentions Caliph ˓Umar Ibn ˓Abd al-˓Aziz of the Umayyads, as well as caliphs al-Mahdi, al-Hadi, al-Rahsid, al-Ma˒mun, and al-Muhtadi of the Abbasids as important leaders who employed hearings in the mazalim to distribute justice.
A session of mazalim requires the presence of five types of assistants. These are the guards, the qadis, the faqihs, the secretaries (to keep records), and the notaries (to witness). The jurisdiction of this court extends to the adjudication of abuse of power related cases involving both officials and nonofficials. It also deals with the issues of restitution of properties taken by force, the supervision of waqf (pious endowments), the enforcement of public order that exceeds ordinary internal security measures, the enforcement of judgments that exceed the authority of the ordinary judges, the enforcement of public duty issues such as Friday prayers, feasts, pilgrimage, jihad, and other extraordinary events. The mazalim is also called to provide arbitration between conflicting parties.
The main difference between the mazalim and the ordinary judicial courts is that the supervisor of mazalim (sahib almazalim or nazir al-mazalim) has extra discretionary power. The ordinary judge is bound by the limitations of conventional judicial system, whereas the supervisor of mazalim enjoys greater procedural latitude. For instance, he may obtain evidence in ways might be unacceptable to an ordinary court's judge. The supervisor of the mazalim also is free to impose arbitrational settlements that are binding on the contesting parties. This option is unavailable to the judge in an ordinary court. In other words, the uniqueness of the mazalim lies in the breadth of its supervisors' discretionary power and political authority.
Nielsen, J. S. "Mazalim." In Vol. VI, The Enyclopaedia of Islam. Edited by C. E. Bosworth, et al. Leiden: E. J. Brill, 1990.