Over 2,000 years ago Atlanteans started worshiping Set. Neptune fought, banished Set, and destroyed his Atlantean cult. He later lived among the Atlanteans for a time as a mortal. Upon his mortal death he was buried with his Trident, this copy ultimately came into the possession of Namor.
Namor was given a copy the Trident by Neptune after completing a series of quest to prove his worthiness for the Throne of Atlantis. 
Neptune's Trident is in part made of Enchanted Adamantine while probably possessing numerous other properties many of which have yet to be completely revealed, the Trident is capable of many things centering but not limited to water-base feats.
- Water Manipulation - Ability to control any body of water, create water elementals, speed ships and other water vehicles with water, create fogs and storms of high intensity, summon waves of water to propel him at great speeds, and create earthquakes by increasing water pressure.
- Mystic Beams - (Shooting from the Trident) It's been constantly depicted that lights or lasers of many colors with many of their own attributes from healing, damaging, cursing and granting.
- Mystic Formation - A unique power to transform objects, willing subjects, and even the wielder, to any desired form with added abilities.
- There are three tridents: the original with Neptune(implied), one left in Pontus and the other given to Namor.
- Either Namor doesn't use the Trident's full potential out of honor or he has little to no knowledge of how it works using it many times as simply a blunt object or a tool to get around quickly.
- A human who spent years studying Atlantis was able to use the Trident's full power soon after getting her hands on it.
- 84 Appearances of Trident of Neptune
- 11 Minor Appearances of Trident of Neptune
- 3 Media Trident of Neptune was Mentioned in
- 57 Images featuring Trident of Neptune
- Item Gallery: Trident of Neptune
Links and References
- Official Handbook of the Marvel Universe Mystic Arcana: The Book of Marvel Magic #1
- Tales to Astonish #70
- Tales to Astonish #76
- Official Handbook of the Marvel Universe Mystic Arcana: The Book of Marvel Magic #1; Appendix: Talismans, Trident of Neptune's entry
- Prince Namor the Sub-Mariner #4
- Tales to Astonish #75
- Namor the Sub-Mariner #40