unable to convince all those who had memorized the Quran to go along with his alterations. Any such alteration also would have been mentioned by Uthman's political opponents and assassins yet none accused him of this. Finally, he argues that if Uthman had altered the Quran, Ali would have restored it to its original state upon the death of Uthman, especially if verses of his rule had been removed. Instead Ali is seen promoting the Quran during his reign, which is evidence that there was no alteration. Manuscripts In the 20th century, the Sanaa manuscript was discovered. It has been radiocarbon dated to the range 578-669 CE with 95% confidence. The manuscript is a palimpsest with quranic verses in both upper and lower texts. The upper text has exactly the same verses and the same order of suras and verses as the standard Quran. The order of the suras in the lower text of the Sana'a codex is different from the order in the standard Quran. In addition, the lower text exhibits extensive variations from the counterpart text in the standard Quran; such that the lower text represents the only surviving early quranic manuscript that does not conform to the 'Uthmanic tradition. The majority of these variations add words and phrases, so as to emphasize or clarify the standard quranic reading. Some scholars have proposed parallels for these variations in reports of variants in 'companion codices' that were kept by individual companions to the Prophet outside of the mainstream tradition of 'Uthman; but these correspondences are much the minority. François Déroche proposes, on palaeographic grounds, a date for the lower text in the second half of the first century AH (hence 672 - 722 CE) and summarises the character of the Sana'a Palimpsest, "The scriptio inferior of the Codex Ṣanʿāʾ I has been transcribed in a milieu which adhered to a text of the Qurʾan different from the ʿUthmanic tradition as well as from the Qurʾanic codices of Ibn Masʿūd and Ubayy". See also Corpus Coranicum Early Quranic manuscripts Biblical and Quranic narratives Prophets and messengers in Islam Quranic timeline Qisas Al-Anbiya Criticism of the Quran Notes References Citations Bibliography Further reading External links History of preservation of Quranic manuscript Read Quran Online Dated Muslim Texts From 1-72 AH / 622-691 AD: Documentary Evidence For Early Islam Islamic Awareness Corpus Coranicum: comprehensive website on early Quran manuscripts by the Berlin-Brandenburg