Al-Kamil fi al-Tarikh by Ibn al-Athir (630 AH/1232 AD) is considered one of the important historical books. Its author excelled in presenting a tragic narrative that expresses emotion and panic, reflecting the magnitude of the tragedy of the Islamic world in the consciousness of contemporaries of the Mongol invasion, which is considered one of the most prominent transformations in the reality of the Islamic world at the beginning of the seventh century AH/thirteenth century AD. This invasion constituted a turning point in the history of the Khwarazmian state and the military, political, social and economic shocks that the Islamic East witnessed later, ending with the fall of the Abbasid Caliphate. Ibn al-Athir described the terror caused by the Mongol invasion and their crimes in people’s souls and the general situation until the year 628 AH/1230 AD, when Ibn al-Athir stopped writing, as he died two years later. His information is distinguished by its accuracy and abundance about the dangerous and sensitive stage in Islamic history. Ibn al-Athir also followed the analytical and critical approach in his narration of the stories.