In 1632, Murad, on reaching the age of twenty-one, took command of the State, and soon showed that he was of very different fibre from his six incapable predecessors. His first experience was an outbreak of the Janissaries, who demanded that the Grand Vizier and sixteen other prominent officials should be executed. Murad was compelled to yield. But he felt deeply the humiliation of his surrender and was determined to avenge it. He gathered round him a faithful band of Spahis, and suddenly, when it was least expected, dealt with the leaders of the Janissaries by putting them to death. This had the effect of cowing that mutinous body. He then devoted himself to the task of purging the State of corrupt and unjust officials of all ranks. He pursued this task with most ruthless energy. On the slightest suspicion officials in the highest positions were secretly put to death by his orders, and their bodies were flung into the Bosphorus. He became a terror to evildoers of all ranks. But he also became bloodthirsty and callous of life in the process. Brutal as were his deeds, they had the effect of restoring order in the State and discipline in the army. Throughout the length and breadth of the Empire his dominant will made itself felt, and his authority as Sultan was soon completely re-established. Murad showed himself equally vigorous and competent as a general. His effective reign, after taking over the government from his mother, did not extend over more than eight years. During this time he personally led two expeditions against the Shah of Persia, each of them occupying two years. In the first of them he conquered Erivan. In the second he recaptured the city of Bagdad, after a most desperate resistance by the Persians. Of the garrison of twenty thousand men only six hundred survived. The Ottoman army was then allowed to sack the city, and thirty thousand of the inhabitants were massacred. The whole province was restored to the Ottoman rule. More than eighty years passed before another war took place with Persia.