By the 640s the Quran existed in written fragments and, above all, in the memories of reciters, and the regional armies had begun to recite it differently. The tradition remembers the general Hudhayfa ibn al-Yaman returning from the Armenian and Azerbaijani front alarmed at the disputes he had heard between the men of Syria and the men of Iraq over how the revelation should be read. Uthman's response was to commission a definitive written text. A committee under Zayd ibn Thabit, who had served the Prophet as a scribe, worked from the sheets kept by Hafsa, a widow of the Prophet, and settled on the dialect of Quraysh where usage differed.
Master copies were then sent out to the main centres (Kufa, Basra, Damascus and Mecca among them, with one kept in Medina), and the order went out that other written versions be withdrawn and destroyed, so that a single consonantal skeleton, the rasm, would stand behind every copy. That standard text is the one Muslims read today. Several of the very oldest Quran manuscripts have been linked by tradition to this moment: the Samarkand Kufic Quran now in Tashkent is venerated as one of Uthman's own codices, and this atlas files that artifact against him for exactly that reason. Modern manuscript scholarship treats such attributions cautiously, the oldest folios are early but not demonstrably the caliph's personal copy, while confirming that a single Uthmanic archetype does lie behind the surviving early tradition.