Mosque architecture has received varying degrees of attention throughout Islamic history, as evident in Islamic historical and geographical manuscripts. However, during medieval Islamic history (Fatimids and Mamluks) mosques took prominence over other buildings. They transitioned from being places of piety to symbols of authority and power. But how did this change transpire? This is related, as this paper argues, to the shifts in jurisprudence (fiqh), knowledge, and power structure across Islamic history. Two types of knowledge existed throughout Islamic history: divine-based knowledge framed by Shari‛a, and desacralized knowledge or rationality. The paper establishes that the expansion of the latter over the former in Islamic jurisprudence, and the introduction of new rational-based derivation sources in fiqh set the ground for the formation of Muslims’ intellectual mindset; one that accepts the application of reason to arrive at decisions and judgments, yet, within the parameters of Shari‛a. This opened the door for rulers to excessively employ rationality in politics to satisfy their own interests, albeit with religious justifications. This resulted in expanding the ruler’s power and its scope of exercitation, part of which is mosque architecture. The paper will explore the epistemic and pragmatic dimensions of mosque architecture. It will examine the rationale of knowledge evolution in Islamic history and its impact on the production and perception of Mosque architecture, with a special focus on the Fatimid and Mamluk eras. Using primary historical texts, the paper adopts a non-empirical, critical methodology.