Between 1904 and 1911, Egyptian intellectuals intensely and acrimoniously debated the history of the conquest of Egypt in the seventh century by Arab tribesmen. For the first time in Egypt’s history, Muslim and Christian polemicists argued over the way in which the story ought to be told, a debate that erupted into the major sectarian crises of 1910-1911. But why did the history of early Islamic Egypt become so contentious at this particular moment? I argue that this urgent turn toward the seventh century was driven by a comparative urge to answer the question: what is colonialism? This question of how to portray the early Islamic past posed significant implications for characterizing the British occupation of Egypt in the present. If the Islamic conquest of Egypt had been legitimate, why was British rule in Egypt illegitimate, imperial apologists asked? Egypt had been a province of the Byzantine Empire in the seventh century, just as it had been an Ottoman province in the nineteenth; the British, like the Arabs, had annexed the territory of an empire state. Yet the analogies that the British had initially thought would normalize their rule would be turned upside-down by their opponents. In the press, comparisons between the seventh and the twentieth centuries became ever-present. The heated debates soon provoked violence when Christian activists overturned the infamous slogan “Egypt for the Egyptians” to argue that only they, the Christians, were Egypt’s rightful rulers, as only they were truly native to the country, the Muslims being later transplants. In response, Muslim thinkers such as Ali Yusuf and Abd al-Aziz Jawish used colonial comparison to explain what they understood to be particular to, and particularly immoral about, British imperialism. It is these articulations—on the coloniality of British rule in Egypt— that form the core of this paper, which draws upon documents found in several archives and in private papers.