Before the advent of colonialism, Arabic was widely used in northern Nigeria where Islam had penetrated before the fifteenth century. The jihād of the early nineteenth century in Hausaland led to the establishment of the Sokoto Caliphate, the revitalization of Islamic learning, and scholars who kept records in Arabic. Indeed, some local languages such as Hausa and Fulfulde were reduced to writing in Arabic scripts. Consequently, knowledge of Arabic is a crucial tool for the historian working on the history of the caliphate.For Ilorin, a frontier emirate between Hausa and Yorubaland, a few Arabic materials are available as well for the reconstruction of the history of the emirate. One such document is the Ta'līf akhbār al-qurūn min umarā' bilad Ilūrin (“The History of the Emirs of Ilorin”). In 1965 Martin translated, edited, and published the Ta'līf in the Research Bulletin of the Centre for Arabic Documentation at the University of Ibadan as a “New Arabic History of Ilorin.” Since then many scholars have used the Ta'līf in their studies of Ilorin and Yoruba history. Recently Smith has affirmed that the Ta'līf has been relatively neglected. He attempts successfully to reconstruct the chronology of events in Yorubaland, using the Ta'līf along with the Ta'nis al-ahibba' fi dhikr unara' Gwandu mawa al-asfiya', an unpublished work of Dr. Junaid al-Bukhari, Wazīr of Sokoto, and works in English. The purpose of this paper is to analyze the information in the Ta'līf by comparing its evidence with that of other primary sources which deal with the history of Ilorin and Yorubaland.