The actual reason for the anti-Uthman movement is disputed among the Shia and Sunni Muslims. According to Sunni sources, unlike his predecessor, Umar, who maintained discipline with a stern hand, Uthman was less rigorous, focusing more on economic prosperity. Under Uthman, the people became more prosperous and on the political plane they came to enjoy a larger degree of freedom. No institutions were devised to channel political activity, and, in their absence, the pre-Islamic tribal jealousies and rivalries, which had been suppressed under earlier caliphs, erupted once again. The people took advantage of Uthman's leniency, which became a headache for the state, culminating in Uthman's assassination.