This entry treats the state religion of Pre-Islamic South Arabia from the second half of the fourth century CE until the region was absorbed by the Sassanians in the seventh century CE. During this time, the ruling Himyarites not only expanded South Arabia to its largest territorial extent ever, spanning from modern Yemen to lower Iraq and perhaps even to Palestine (Robin, 2012), but they also adopted a new form of monotheism, which was heavily influenced by but distinct from Judaism. This Judaizing Himyarite Monotheism worshipped a monotheistic deity called either Raḥmānān "The Merciful" or ʾIlān "God." While details about this religion are sparse, Philostorgius provides some hints concerning its character. He records that Constantius II sent an expedition to Himyarites (called "Homeritae") in South Arabia in what would be the time of Thaʾrān Yuhanʿim (324-375 CE). He describes the Himyarites as "of the Israelitish family" but notes that they sacrificed to various native gods. There were also Jews in the royal court, who are said to unsuccessfully oppose the Christian embassy, as Philostorgius alleges that the Himyaritic king converted to Christianity and built three churches. Yet during that time, public state sponsorship of polytheism did not cease in the epigraphic record. It is not until the reign of Thaʾrān's son, Malkīkarib Yuhaʾmin (375-400 CE; Robin, 2012), that worship in the monumental display texts was almost unilaterally directed to Raḥmānān, with mentions of the old gods becoming almost extinct (yet, they still persist in the less public stick inscriptions; Stein, 2009). Explicitly Jewish inscriptions also begin appearing in fourth century CE; albeit, the exact relationship of South Arabian Judaism with other outside contemporary Jewish groups remains unclear (Hughes, 2020a). There is further uncertainty as to whether their God, who is twice explicitly called "The Lord of the Jews," was originally identified via syncretism with Raḥmānān or if he was thought to be a separate distinct but still monotheistic divinity, who existed alongside Raḥmānān (Gajda, 2017). Regardless of this potential distinction, the name Raḥmānān does eventually get absorbed into local Christian and Jewish vocabulary as a moniker for "God." During the fifth century CE, the state continues to sponsor Himyarite Judaizing Monotheism all-the-while tensions between Christians and Jews begin to rise. The Martyrdom of Azqir (Conti-Rossini, 1910) records a priest named Azqir being arrested for proselytizing. He was then brought to trial before the Himyarite king (who is not said to be Jewish) and the Jews on his court. The text ends with Azqir's martyrdom, with the narrator noting that thirty eight Christians had received a similar fate during that king's reign. In the sixth century CE, state sponsorship of Judaizing Himyarite Monotheism disappears as the Ethiopian Aksumites gradually gained control of South Arabia and installed a Christian king, Maʿdīkarib Yaʿfur, on the South Arabian throne in 519 CE. Around this time, the Christians began to persecute the Jews. When Maʿdīkarib dies a few years later in 522 CE, a Jewish prince named Yūsuf Asʾar Yathʾar (Arabic Dhū Nuwās) began a series of military campaigns seeking to expel the Aksumites and to burn their churches (Robin, 2012). This culminated in the slaying of the Martyrs of Najrān in 523 CE, wherein the Jewish King Yūsuf gained control of Najrān by artifice and then systematically kills the Christians. This event gave justification for the Aksumite King Kaleb to invade South Arabia, during which he killed Yūsuf and violently seeks vengeance on the Jews. South Arabia thereafter would remain under Christian control until it was eventually acquired by the Sassanians.