The cautious conversion of the kings of Ḥimyar to monotheism in the fourth century CE was influenced by the beliefs of a local Jewish community. This chapter clarifies the relationship between South Arabian Jews and Jewish sympathizers and offers an interpretative framework for the monotheism of fourth- and fifth-century Ḥimyar, which contextualizes the choice of South Arabia’s elites to become Jewish sympathizers. The process of conversion to monotheism also shares features with the first stage of Christianity in Aksūm and the Graeco-Roman world, as well as the henotheism of pre-Islamic North Arabia. It argues that the Ḥimyarite kings’ cautious conversion follows a broad Late Antique trend which aimed to ease the transition for their subjects and/or to assume a neutral position towards the developments of the surrounding empires. In the brand-new kingdom of Ḥimyar, the cult of a single, institutionalized and translocal deity provided a strong mechanism for establishing identities that were reshaped in a wider syncretistic framework through a sociopolitical exploitation of cults characteristic of the broader late antique world.