In the Eleusinian mysteries Proserpine no doubt played an important part.
At Rome Proserpine was associated with Ceres (the Roman representative of Demeter) in the festival of the Cerealia (April 12 to 19), she was represented as the wife of Dis Pater (the Roman Pluto), and was sometimes identified with the native Latin goddess Libera.
They celebrated the festival of Demeter when the corn began to shoot, and the descent of Proserpine when it was ripe.
In Greek mythology Demeter and Proserpine were closely associated, being known together as the two goddesses, the venerable or august goddesses, sometimes as the great goddesses.
Demeter and Proserpine were worshipped together by the Athenians at the greater and less Eleusinian festivals, held in autumn and spring respectively.
Corresponding to Proserpine as goddess of the dead is the old Norse goddess Hel (Gothic Halja), whom Saxo Grammaticus calls Proserpine.
So all that year not a blade of corn grew on the earth, and men would have died of hunger if Zeus had not persuaded Pluto to let Proserpine go.