When did Demeter and Zeus marry?
Demeter and Zeus did not marry, but did have the child Persephone/Kore.
Hm, some yes. Hera was married to her brother Zeus. Zeus was married to Hera, but had wives before her and consorts and mistresses after. Hades married Persephone, daughter of Zeus and Demeter (a sister of Hera). Poseidon married Amphitrite. Demeter had children with Zeus, Poseidon, Iasion and Karmanor but did not marry. Hestia never married, remaining a virgin goddess although both Poseidon and Apollo wished to marry her.
It started with kronus....then his wife bore 6 children...Zeus,Hera,Poseidon,Hades,Demeter,And the godess of hearth......then Zeus bore many children....I only knew much some of them....Hermes,Athena,Aphrodite,Apollo and Artemis.....Then Demeter bore a child by Zeus her name is Persephone then Hades marry her :))Zeus have demigodes who is born a hero...like Hercules :D