During the Karakhanid period, when the Turks were included in the Islamic environment, they continued to produce works with the old writing system, namely the Uyghur script, as well as the Arabic alphabet. There are copies of Atebetü’l-Hakâyık, one of the works of this period, in Uyghur letters, Arabic letters, and both Uyghur and Arabic letters. In this article, the Ayasofya [Hagia Sophia] copy of Atebetü’l-Hakâyık, which was copied by Şeyhzâde Abdürrezzâk Bahşı in 1480 with Uyghur letters at the top and Arabic letters at the bottom, is studied through lines with Uyghur letters. First of all, in order to determine the writing style of Şeyhzâde Abdürrezzâk Bahşı, Ayasofya copy of Atebetü’l-Hakâyık, Mahzenü’l-Esrâr, in the compilation in which Ayasofya copy is also included, Fatih Sultan Mehmet’s Uyghur lettered yarlıg (edict) and the tuyugs in Kutadgu Bilig belonging to Şeyhzâde Abdürrezzâk Bahşı, are compared by means of sample words. Then, the initial, the medial and the final forms of the Uyghur letters in the Ayasofya copy are determined. And, a particular code is given for each of these different Uyghur letterforms. The sounds corresponding to the coded forms in the copy are also shown in parentheses. The paired forms with Arabic letters written above or below the Uyghur letters, and the Uyghur letters used in the writing of Arabic-Persian words have also been identified. Word examples from the text are given for the Uyghur and Uyghur-Arabic paired letterforms and the Uyghur letterforms used in the writing of Arabic-Persian words. In addition, the writing and phonetic features of Uyghur letters are also compared with lines in Arabic letters from time to time within the scope of this article.

Atebetü’l-Hakâyık, Şeyhzâde Abdürrezzâk Bahşı, Mahzenü’l-Esrâr, Fatih Sultan Mehmet’s yarlıg, Paleographic study.