Abstract
The scientific study of the legacy of Khoja Ahmad Yassawi (d. 562/1166) commenced in the 20th century under the direction of Fuad Köprülü (1890-1966). Despite the numerous significant studies that have been conducted on Ahmad Yassawi and Yassawism, there is a discrepancy in the available information regarding the year of his birth. Nevertheless, the precise date of Ahmad Yassawi's birth remains uncertain. However, there is clear information regarding the date of his death and the duration of his life in sources such as the Neseb-name. In light of the aforementioned data, it is feasible to ascertain the year of Ahmad Yassawi's birth. Nevertheless, some medieval sources present differing perspectives on this matter, thereby rendering it open to debate. It was thus deemed appropriate to undertake an analysis of the year of Ahmad Yassawi's birth. This article presents an attempt to determine the years of Ahmad Yassawi's birth and death based on primary sources, with a particular focus on genealogical trees. In conducting this study, the methods of deepening sources and comparative analysis were employed. Additionally, determinations and evaluations have been made regarding the bibliography of Ahmad Yassawi.