Poseidon

Romans adopted Poseidon, the god of the seas, in their pantheon under the name of Neptune. (PROSE: Byzantium!) In the City of the Saved the Romans demoted to a minor god as there were no real seas in the City, replacing him and Dis Pater with Romulus and Civitata. (PROSE: Of the City of the Saved...)

Neptunium was named after Neptune. (PROSE: Elementary, My Dear Sheila)