Last year, I spent each day of the Megalensia focusing upon one aspect of the (Romanized) cultus of Magna Mater/Cybele. One the first day, for example, I focused on some aspects of the general history of the festival, and some of its modern implications and usages.
This year, however, I'd like to kick off by drawing your attention to something else. The background of the cultus as it was transmitted to Rome was Phrygian. However, the culture of Phrygia–as well as a great deal of the other parts of Asia Minor, including Bithynia–was Thracian in origin, or at least was connected to it. Scholars, in fact, speak of Thraco-Phrygian matters in relation to the cultus of Cybele on many occasions. The cultus of Sabazios also gets compared to the rites of Magna Mater in a variety of Greek and Roman contexts, and both Zeus and Dionysos are connected into the extant mythology–with Zeus being in a certain sense the "progenitor" of much of what occurred in the later myth through his lusting after Cybele and spilling his seed on the ground; and Dionysos being driven mad, but seeking his eventual cure for his madness from Cybele.