All of the classics courses I've taken seem to focus on Christianity's rise (persecutions from Nero to Diocletian, conversion of Constantine I, conversions by various barbarian kings and chieftains, etc.), but I want to know more about the decline of Graeco-Roman polytheism.

At what point did the pagans fall into the minority? At what point did they themselves begin to suffer persecution? What is its last attested evidence in Christian Europe? Did it die out later in the Latin West, or the Greek East? I just want a general outline of how the old religion clung to life then disappeared. Were most farmers in say, Gaul or Italy still praying to Bacchus, Jupiter, etc. in 300AD? How about in 600AD?