This was a very clever move by Umar because he had chosen people who would not readily favour Imam Ali (A). Furthermore, he had instructed that if any of these six challenged the appointment of the person who was finally declared Caliph, he should be killed.
After his death the nominees met but could not reach any conclusion. At last, Abdur Rahman said that he would forego his claim for the Caliphate if they allowed him to elect the Caliph. Uthman agreed to this but Imam Ali (A) said that he would only agree if Abdur Rahman promised not to give consideration to family but judge only on merit. He said this because Uthman was the brother-in-law of Abdur Rahman and the two were friends. Abdur Rahman accepted the condition and then talked to each of the candidates privately.
Zubayr was in favour of Imam Ali (A), Talha was not present in Madina and how Sa'd voted is uncertain. Both Imam Ali (A) and Uthman pressed their own claim. Therefore the selection narrowed down to these two men.
The next day the mosque was crowded because everyone wanted to know who their new Caliph would be. Abdur Rahman had discussed the situation with Amr al-Aas, who was a shrewd politician with no religious morals.
Acting on Amr's advice, Abdur Rahman asked Imam Ali (A) to become Caliph as long as he would agree to rule by the Holy Qur'an, the teachings of the Holy Prophet (S) and the practices of Abu Bakr and Umar.
As expected, Imam Ali (A) agreed to the first two conditions but flatly refused to follow the practices of Abu Bakr and Umar. When Uthman was given the same conditions, he agreed at once and was thus declared the third Caliph.
Imam Ali (A) told Abdur Rahman,
"It is not the first time I have been deprived of my rights, but you have not been free of self interest in your decision."
On hearing these words Abdur Rahman warned Imam Ali (A) that Umar had said that the one who defies the selection should be killed, whereupon Imam Ali (A) left the gathering in disgust.
The choice of Uthman was a bad mistake and in later years the man almost destroyed the faith and dignity of the Muslims. His first speech to the public was a very poor effort and he lamely finished by saying,
"We were never preachers but the Lord will teach us."
From the first day of his rule, Uthman began systematically replacing the governors of the major provinces with his own relatives from the Bani Umayyah.
Thus, in Kufa he appointed his drunkard brother Waleed to replace Sa'd bin Waqqaas. In Egypt he replaced Amr al-Aas with his foster brother Abdallah bin Abi Sarh, who has been cursed in the Holy Qur'an (Surae An'am, verse 93) for inventing lies and saying that he had revelations from Allah.
He recalled back to Madina Hakam bin al-Aas, who had been exiled for life by the Holy Prophet (S). Hakam was Uthman's uncle and Uthman made Hakam's evil son Marwan his secretary and gave him huge gifts from the property of the Muslims. He also gave Marwan the property of Fadak and made him his son-in-law.
As Uthman began to squander the public money on his relatives openly, resentment against him grew from all quarters. Ammar Yasir, an old and respected companion of the Holy Prophet (S) challenged Uthman's conduct and was severely beaten for his words. This action against a man like Ammar outraged the people.
In Syria, another great companion of the Holy Prophet (S), Abu Zar Ghifari, was going around warning the governor Muawiya and the people against their evil ways.
Muawiya sent Abu Zar to Madina where Uthman had the bad manners to insult him. He then cruelly banished the old man to Rabazha, in the desert of Najd, where he died of neglect two years later.
Uthman's high-handed behaviour and the cruelties and excesses of his worthless governors caused unrest throughout the empire. Riots broke out everywhere. In Madina itself there were calls to remove Uthman.
The Caliph was beset from all sides and turned to Imam Ali (A) to appeal on his behalf. Imam Ali (A) agreed, provided Uthman publicly apologised for his mistakes.
In despair, Uthman mounted the pulpit and with a voice broken by sobs and tears he begged the forgiveness of Allah and assured the public that he was repentant. Because of his apologetic state and the intervention of Imam Ali (A) the people were quietened.
However, the Egyptians insisted that their cruel governor Abdallah bin Sarh be replaced by Muhammad the son of Abu Bakr. He was a pious man who had been raised from his infancy by Imam Ali (A), who had married Abu Bakr's widow.
Uthman agreed to this demand, but secretly sent a letter to his brother in Egypt warning him of the situation and advising him to kill Muhammad bin Abu Bakr on his arrival.
Unfortunately for Uthman, this messenger was intercepted on the way to Egypt by Muhammad himself. The Egyptians were outraged by the Caliph's treachery and returned to Madina in a furious mood. The news of his actions spread and finally Uthman had to take refuge in his palace which was then surrounded by people calling for his blood.
After a siege of 40 days the palace was broken into and Uthman was killed by repeated stab wounds. His body was buried in the graveyard of the Jews. He was 82 years old and had ruled for 11 years.