The primary purpose of this article is to reconstruct the date, location, and significance of Ayutthaya's Shi‘ite enclave within the former Siamese capital during the seventeenth century. This reassessment is based on a mixture of Persian, Thai, and European sources that clarify the confused picture generated by European cartographers that has for too long cast a shadow over Muslim studies in Thailand. Following a summary of extant explanations and a description of my primary sources and methodological approach, I summarise two aspects of Muslim presence in Ayutthaya. First, I introduce readers to connections between the incremental growth of the Muslim presence in Ayutthaya during the sixteenth century with geopolitical developments on the eastern littoral of the Bay of Bengal. Second, I present the range of accounts provided in primary sources specifically mentioning Ayutthaya's Muslim enclave. Having orientated readers to the origins of the Muslim presence within Ayutthaya's citadel, I incrementally introduce annotated portions of Thai and European maps. These clarify confusion about where and when this Shi‘ite mosque was constructed. I conclude with comments about how this reassessment brings into focus the presence of Shi‘ite ‘alid piety, Shi‘ite polemics about local Sunnis, Siamese conversion to Shi‘ism, and distinctions between these “Moors” and “Malays.”