In this presentation, I will highlight the influence of Catholic conservative thought, particularly that of the Jesuit order, on the development of a political concept of conservatism in the Arabic language during the 19th century. Influenced by the French and European experience, Arabic conservatism emerged as a post-tanzimat (Ottoman reforms) concept that reconciled the tension between the authority of the modern state and that of religious institutions by adopting the model of the confessional state. As a political ideology, conservatism is a modern concept. This historical and conceptual assertion also relies on the historical semantics of "conservatism" in Arabic. Before the 1860s, the term muḥāfiẓ (pl. muḥāfiẓin) referred to a governor of a city or a commander, and muḥāfaẓa denoted guardianship and preservation, without any specific political connotation. In the 1870s, the term experienced significant politicization, which delineated a contested political meaning. In texts and lexicons published during this period, the term "conservation," hifẓ, meant to preserve, while "conservatism" meant "al-muḥāfaza ʿalā al-nizāmāt al-qadīma," preservation of the old order, norms, or laws. "Conservative", muḥāfiẓ indicated a proponent of the conservative ideology and party (ḥizb al-muḥāfiẓīn). The earliest manifestations of these semantic changes can be found in texts published by the Jesuits in Beirut, which played a significant role in shaping an early response to concepts that are central to modern political philosophy, including citizenship, the nation-state, individual autonomy, and the overall relationship between religion and the state. What is the context for the emergence of the political concept of "conservatism" in the Arabic language? Additionally, how did this concept influence the Islamic reform movement?