Diseases in the Medieval Islamic world in the Context of Ibn Athir's work titled al-Kāmil fi al-Tārīh

History aims to shape the future by investigating and learning from past events. To achieve this mission, the past must be evaluated accurately. To do so, it must consider all the factors that affect human life and determine the course of human history. In this context, diseases, which emerged alongside human history and are among the most important factors affecting human life throughout history, must also be identified. Failure to consider the impact of diseases on the course of history will result in inadequate assessments of the past. Unfortunately, because historians have focused all their attention on political events, the subject of diseases has not received the attention it deserves, or political and military events have obscured it. To address this need, albeit at least a little, in this field, Ibn al-Athir's work, al-Kāmil fi al-tārīh, one of the most reliable sources of the Middle Ages, was examined. This work covers events from creation to the early 13th century in a chronological order. Our thesis, "Diseases in the Medieval Islamic World in the Context of Ibn al-Athir's al-Kāmil fi al-Tārīh" aims to examine Ibn al-Athir's work and identify the diseases mentioned in it. Furthermore, we attempt to identify the individuals and societies affected by these diseases and how epidemics affect social, economic, and political life.