There are a number of inscriptions from Asia Minor and elsewhere in which we find ὕψιστος, ‘the Highest’, or Θεòς ὕψιστος, ‘the Highest God’. The word ὕψιστος is used of Yahweh in the Septuagint, in the NT, in Jewish Pseudepigrapha and by other Jewish authors. It is also used in classical literature and inscriptions of pagan divinities, most frequently of Zeus. The problem with the inscriptions is therefore to discover when the term is used by Jews to refer to Yahweh and when it is used by pagans to refer to a pagan divinity. In fact, at the hands of Cumont, the body of evidence to be examined here gave rise to a complex and influential theory of syncretism involving Judaism in Asia Minor. He argued that the title ὕψιστος, whilst being used of Yahweh, was used of Zeus because of Jewish influence. Similarly, in Asia Minor ‘Theos Hypsistos’ was used in inscriptions by both Jews and pagans as the name of the God of Israel. Associations of the cult of ‘Theos Hypsistos’ were formed by these people, associations which adopted some but not all of the practices of the synagogue. Further, again under Jewish influence, ‘Theos Hypsistos’ was used of the deity Sabazios. This, with other evidence, led Cumont to believe that the two deities were identified in certain thiasoi. Thus, some groups which worshipped Θεòς ὕψιστος in fact represented a fusion of the two cults – Yahweh and Sabazios.