Kitāb al-kharāj (Book of taxation)is a classic text on fiqh (Islamic jurisprudence), written by Abū Yusūf Yaʿqūb Ibrāhīm al-Anṣārī al-Kūfī (died 798; 182 A.H.) at the request of the Abbasid caliph Hārūn al-Rashīd (763 or 766-809). Abū Yusūf was the most famous student of Abū Ḥanīfa and along with his illustrious teacher is considered one of the founders of the Ḥanafī school of law. In the introduction to the book, Abū Yusūf describes how the caliph asked him to write a work treating the collection of al-kharāj (the tax collected from non-Muslims), al-ʿushūr (a tithe payable by Muslims), al-ṣadaqāt (alms), and related matters requiring attention and action. Hārūn al-Rashīd’s expressed intent was to use the work to address the oppressed condition of his subjects and to improve their economic well-being. The work includes such chapter headings as “A description of the land [subject to] tithing and al-kharaj, and of Arabs and non-Arabs and idolaters and the people of the book [i.e., Christians and Jews] and others.” The work also contains a considerable amount of historical and geographical information on the early centuries of Islam. This can be seen, for example, in the account of the conquest of Byzantine and Sassanian lands contained in the chapter faṣl fī arḍ al-shām wa al-jazīra (Chapter on the land of Syria and Mesopotamia). This manuscript copy of Kitāb al-kharāj was completed in Damascus, near the end of Rajab, 1144 A.H. (January 1732). The table of contents, which appears to have been scattered and reattached to the book with its folios out of sequence, was apparently written about a century later, on the Dhū al-Ḥijjah, 16, 1245 A.H. (June 1830), in Sarajevo (present-day Bosnia and Herzegovina). This work has been reprinted in multiple editions in modern times and has been translated from the original Arabic into English, Russian, and French.