In Shawwal 35 AH, three separate groups of malcontents gathered in Egypt, Kufa and Basra. The Egyptian group — roughly three to four thousand men — was the most motivated, led by figures such as Muhammad ibn Abi Hudhayfa and Muhammad ibn Abi Bakr, who harbored personal grievances against ʿUthman ﵁. The Kufan group gathered around grievances against Saʿid ibn al-ʿAs ﵁ and the earlier removal of Saʿd ﵁; the Basran group around accusations of mistreatment by local governors.
The three groups moved toward the Hijaz seemingly independently, but their timing was so precise that coordination presumably took place. Their professed aim was to lodge complaints with the khalifah; their true intention differed per group. Some rebels wanted political reforms — the removal of certain governors, the return of certain waqf funds to the treasury, redistribution of state resources. Others — above all within the Egyptian vanguard — had already resolved to put ʿUthman ﵁ to death.
By mid Dhul-Qaʿdah the first rebel detachments arrived around Medina. They established themselves in three rings around the city: the Egyptian ring on the south side, the Kufan ring on the east side, the Basran ring on the west side. The total rebel force — between eight and ten thousand armed men — was not large enough to destroy Medina, but sufficient to isolate the city and besiege the authority of ʿUthman ﵁ within his own house.
ʿUthman ﵁ received the first rebel envoys with the courtesy that was characteristic of him. He heard their complaints, promised to open investigations, and held out the prospect of removing certain governors. The envoys returned to their camps. What they claimed to have seen is not recorded; what is certain is that the siege, instead of ending, only worsened.