This paper investigates Western writings on Ottoman Algeria as more than mere historical documentation. The records left behind by consuls, diplomats, captives, clergymen, travelers, and intelligence agents form a rich and diverse body of texts that, despite this diversity, converges on a single common purpose: gathering strategic intelligence that paved the way for the French invasion of Algeria in 1830. The research rests on four main axes: a typology of Western authors and their backgrounds; the writing techniques used by these authors and their sources of knowledge; the political, religious, scientific, and military interests lurking behind their writings; and finally, an analysis of the stereotypical duality permeating this literature as historical testimony and ideological construct simultaneously. The analysis of these writings reveals a structural tension between the documentary nature of this literature and the inherent ideological bias rooted in the historical conflict between Christianity and Islam, and the broader colonial policy of Europe. At the same time, the study identifies a critical current within Western literature itself, embodied by those Western authors who challenged prevailing stereotypes about Algeria. The paper concludes by stressing the methodology of “double-reading” as an indispensable necessity for the historiography of Ottoman Algeria.