I've seen this concept ~ of the gods defeating another power and imprisoning them ~ in Greek myths and tales, but I'm curious to know if it's found in other ancient religions. So far, my research has been frustrated (perhaps I'm using the wrong resources or search terms). Does anyone know if this is a recurring theme, a modern story element or isolated to just a few belief systems?
It certainly isn't unique to greek mythology. Norse mythology includes the binding of loki underground with poison dripping onto him and of Fenrir the wolf. You might also see later conceptions of Satan and his fallen angels as a case of imprisoned 'gods'.
As a motif it allows enemies to be both defeated and yet somehow present and potentially threatening (including the idea they either will or at least might break their chains in some apocalyptic context). Perhaps in some contexts the idea of divine beings simply dying seems unnatural.