According to Greek mythology Hephaistos (here the Etruscan god Sethlans) was cast out of Olympus either by Hera, due to his deformity, or by Zeus, for defending his mother from his advances. His subsequent return is a favorite subject for vase painters in the 6th century B.C. Hephaistos resists the invitation to return to the gods' favor, until Dionysus intoxicates him and places him on a donkey accompanied by revelers, as seen here.
For the Return of Sethlans on two Etruscan panel amphorae see nos. 8-9, p. 405 in Krauskopf, "Hephaistos/Sethlans," in LIMC.