Zeus , Hera , Poseidon , Ares , Hermes , Hephaestus , Aphrodite , Athena , Apollo , and Artemis are always considered to be Olympians . Zeus , Hera , Poseidon , Demeter , Athena , Dionysus , Apollo , Artemis , Ares , Aphrodite , Hephaestus and Hermes .