Legal right that a court has to receive a case first. For example, the Constitution makes it clear that the Supreme court has 'original jurisdiction' when states sue states and in cases involving high-level diplomats.
The nations debt was the most important cause, but another one would be the clergy to pay taxes.
The expanding of the muslim Empire in the years following the Prophet Muhammad's death led to the creation of the caliphates, occupying a vast geographical area and conversion to Islam was boosted by missionary activities particularly those of Imams, who easily intermingled with local populace to propagate the religious teachings.
