In the extension of the Muslim dominions, the Quraish had played the leading role. Ali was a Quraish, but he could not win the support of the Quraish. In his book Ali, the Superman, Dr. Mohyuddin has observed as follows about the opposition of the Quraish to Ali: "Ali hoped to establish a world-Islamic empire, a kingdom of God on earth, where peace was to reign supreme and mankind could move steadily towards perfection. That he failed so completely, is one of the enigmas of Islamic history. The student is perplexed, and indeed despondent, when he discovers that the entire tribe of the Quraish gave whole hearted support to the first two Caliphs. Abu Bakr, who belonged to the tribe of the Banu Adi, but not to their two successors, also belonged to the Quraish tribe. It is teaming indeed that they obeyed Abu Bakr and Umar blindly, but deserted Othman and Ali, whom they bitterly opposed and finally murdered. From the moment that Ali came to power, he was resisted and obstructed by the Quraishite, in spite of the fact that the aristocratic Quraish knew that Ali had noble blood in his veins, blood which had cowed in the veins of the Holy Prophet, and that in addition he had those personal traits of character, which made him unique amongst all the persons of his age. Ali's knowledge, piety, bravery, generalship, services for the propagation of Islam, and his achievements on the battlefield for the defense of Islam, made him superior to the first two Caliphs. He was superbly equipped to fill the office of the Caliph, yet the entire race seemed to have taken up arms against him. In spite of his qualities of mind and spirit, he seems to have been sacrificed to the prevailing tribal spirit of his countrymen. Perhaps it was his superiority, more than anything else, which lead to his downfall. He knew himself to be superior to his contemporaries, and he hated the petty tribal chiefs of the Quraish who were interested only in their self-aggrandizement. What is more, he let them know his contempt for them, seldom bothering with the formalities of consulting them and frequently acting independently of them, in defiance of established custom."