The construction of al-Jami al-Aqmar is a potent example of the symbolism imbibed within Fatimi architecture. Historians of Fatimi architecture have discussed Maulana al-Imam al-Aamir’s SA reasons for constructing this masjid, yet a holistic understanding of these reasons requires insightful reference to Fatimi philosophy. A core belief of the Fatimi faith is that an Imam, son succeeding father, direct descendent of the Prophet Mohammed SAW, is ever-present on earth. However, the Imam may choose seclusion, which is often compared to nightfall in Fatimi literature and lore. The Imam being the sun, his radiance and guidance reaches his followers during his seclusion through his representative and Da’i–the moon. Imam al-Aamir SA knew that a long seclusion was imminent and that his representatives, the Duat Mutlaqin SA would continue to guide believers during this difficult period. Luminous like the moon, al-Jami al-Aqmar, by virtue of its name and its existence, is testimony to this reality.
A superior feature in later Fatimi architecture is the muqarnas, seen clearly in this picture, adjacent on both sides to central arch over the central doorway. A muqarnas is a squinch, and, as a design element, is usually seen as a cluster of miniature squinches, appearing as a series of small niches and producing a sort of cellular structure. Though present in Baab al-Futuh as well as al-Jami al-Juyushi, their beauty and import is best viewed in al-Jami al-Aqmar. The façade of al-Aqmar displays many such niches but the use of a muqarnas as a cornerstone is a pioneering Fatimi contribution. This cornerstone, referred to as al-Rukn al-Mukhallaq, the perfumed cornerstone or al-Mukhawwaq, the wide cornerstone, widened the edge of the masjid creating much needed extra space for the narrow cross streets.