The devotees of Demeter at Ephesos were not the only association that included mysteries and initiations in its activities.  (You can read more about the mysteries, including those of Dionysos, on my website here).   We know of several other associations there that engaged in mysteries, including groups of Dionysos-initiates.   Sometimes there could be cooperation among such groups (rather than the rivalries which I outline in one of the chapters in my new book, roughly sketched here).

A particularly interesting case in the mid-late second century involves the amalgamation of two groups to become the  “Demetriasts and initiates of Dionysos Phleos before the city” (177-92 CE; IEph 1595).  Here is an earlier inscription set up in honour of the emperor Hadrian by a group that is likely to be identified with the one that later joined with the Demetriasts:

Emperor Caesar Trajan Hadrian Augustus, son of god Trajan Parthicus and grandson of god Nero, greatest high-priest, with tribunician power, three times consul.  The initiates before the city, enthroned with Dionysos, (honoured the emperor) when Cl. Romulus was priest, Cl. Eubios was hierophant, and Antonius Drosus was superintendent.  Theodotos, son of Theodotos Proclion, initiation-leader, with his children, Proklos, hymn-singer, and Athenodoros set up this honour from their own resources (IEph 275; 117-138 CE).

Click on “Translated inscriptions” in the tag line above or in the sidebar to read other inscriptions in this series.