The fact that by the end of the fourth century CE the Himyar kings converted to a Jewish monotheism and subsequently no more polytheistic inscriptions are composed, is well known. However, the process of this conversion has not been considered so far. Based on the data obtained by analyzing the epigraphic and literary sources, the onomasticon, and the lexicon, as well as a comparison with other examples (Rome, Sāsānids, Aksum), the conversion of the individual kings and the Ḥimyar as a whole may be fitted into the models of the conversion career (Gooren) or voluntary association (Bentley). It turns out that the conversion of the Ḥimyari kings to a Jewish monotheism is not the result of strictly political macchiavellian decision but must have been based on personal belief. By converting to a Judaism the kings Malikkarib Yuhaʾmin and ʾAbkarib ʾAsʿad were trying out a new way to legitimize and secure their power permanently. Since their conversion met with success their family, the tabābiʿa of Arabic tradition, became the most enduring Ḥimyari dynasty and Jewish monotheism in southern Arabia prevailed.