day are preserved in private collections, museums, and libraries as primary sources, especially for historical research and various other disciplines. These works are invaluable not only for the wealth of knowledge they contain but also for their reflection of the social, political, and cultural structures of the period to which they belong. These manuscripts, with both the information they hold and the historical and cultural significance they carry, place the institutions that preserve them at the center of academic studies and the conceptualization of civilization. Libraries that have preserved manuscripts written over centuries and represent the collective memory of our civilization are critically important centers for historical and scientific studies. One such library is the Khalidiya Library, one of the leading cultural institutions of 19th-century Jerusalem. Established during the Ottoman period as a waqf (endowment) library, it serves as a significant repository that carries the rich scholarly heritage of the Islamic world to the present day. In this regard, the manuscripts housed in the Khalidiya Library are of great importance for understanding the historical, religious, and cultural identity of Jerusalem. These works also shed light on the city's intellectual and socio-cultural life. A review of the literature reveals that various aspects of the history of librarianship during the Ottoman period have been examined. However, comprehensive studies focusing on the libraries in Jerusalem and the systematic classification of the works housed in these libraries would make significant contributions to the study of the development of Islamic legal thought and research on the history of Jerusalem. This study aims to conduct a systematic analysis of the usul al-fiqh (principles of Islamic jurisprudence) literature and fatwa collections in the manuscript collection of the historical Khalidiya Library, located in Jerusalem, the third holiest city in the Islamic world. The manuscripts in this library have generally been classified by subject, and cataloging efforts have also been undertaken. The Khalidiya Library’s collection includes valuable works in fields such as tafsir (Quranic exegesis), hadith, theology, Islamic jurisprudence, Sufism, literature, and history. Of particular note is the approximately 600 fiqh manuscripts, which constitute nearly half of the library’s collection. The extensive presence of commentaries, fatwa collections, usul al-fiqh works, and manuscripts on waqf (endowments) related to the Hanafi school of law, the official madhhab (legal school) of the Ottoman Empire, provides a rich resource on the legal theory and practice of the period. This paper will begin by presenting an overview of the library's establishment, growth, and current state. Subsequently, a list of the usul al-fiqh manuscripts and fatwa collections in the library’s rich collection will be provided, accompanied by an analysis of their characteristics, technical features, and content. The study will first address the historical development and current status of the library and then offer a detailed inventory of the usul al-fiqh manuscripts and fatwa collections within its collection. This inventory will cover the codicological features, content analysis, and historical significance of the works. In doing so, the study aims to shed light on the place of Jerusalem in the history of Islamic law and provide researchers with a systematic guide to these valuable resources.