Poseidon is the God of the Seas and Earthquakes in Greek mythology, and brother of Zeus, King of the Gods, and Hades, God of the Underworld. A son of the leaders of the Titans, Cronus and Rhea, like his other siblings he was swallowed by his father, due to Cronus's fear that his children would overthrow him just as he had overthrown his father Uranus. After the youngest child Zeus managed to escaped this fate and had grown up, he caused Cronus to regurgitate his siblings, including Poseidon, and subsequently led them in a war against the Titans. After the Titans were defeated, Zeus, Poseidon and Hades drew lots to decide their domains, with Poseidon receiving control over the seas, Zeus the sky and Hades the underworld, with the land being shared between them.
As with the other Olympians, Poseidon plays a role in many stories of Greek mythology and their derivatives. One of his sons was the hunter Orion, who gained the love of Artemis and as Poseidon's son was able to walk on water. Poseidon gave the divine horses Balius and Xanthus to Peleus as a wedding gift, who would later be used to pull the chariot of Peleus's son, Achilles. Minos, king of Crete, had a promise with Poseidon to sacrifice a bull presented from the sea god, however one year he broke the promise and sacrificed another bull instead. For breaking the promise, Poseidon cursed Minos's wife Pasiphae, causing her to have sexual desires towards bulls and resulting in the birth of Asterios.
In the story of Medusa, which differs from her actual life, Poseidon's pursuit and violation of her is responsible for her subsequent curse and transformation into a monster by a goddess, either Poseidon's wife or Athena, and his children with her, Pegasus and Chrysaor, are born from her neck after she is decapitated by Perseus. In another story, he had his way with the Lapith Caenis but granted her a wish as compensation, transforming her into the male Caeneus and giving him impenetrable skin, so as not to suffer the same fate again.
Okeanos: The Four Sealed Seas of the EndEdit
Prior to the events of the Okeanos Singularity, Francis Drake had reached Atlantis after a seven-day voyage and encountered Poseidon, who intended to flood civilization. Drake subsequently defeated Poseidon, taking a Holy Grail which was in his possession and causing Atlantis to sink. Drake's grail would interact with the other grail which was planted into the era to disrupt the Human Order Foundation, resulting in the endless sea of the Okeanos Singularity.
Fate/Grand Order: Cosmos in the LostbeltEdit
Götterdämmerung: Eternal Ice-Flame CenturyEdit
As God of the Seas, Poseidon held authority over the seas. Poseidon's primary weapon is a trident, which is said to cause earthquakes when he strikes with it.
- ↑ Fate/Grand Order material II - Orion, pg.192-201
- ↑ 2.0 2.1 Fate/Grand Order - Okeanos: The Four Sealed Seas of the End
 Fate/Apocrypha material - Encyclopedia: Tempestuous Immortal Chariot [Noble Phantasm], p.178 [T]
Tempestuous Immortal Chariot [Noble Phantasm]
Troias Tragōidia. The Noble Phantasm of Rider of Red, Achilles. An A rank chariot driven by three steeds. The horses consist of the two divine horses which the sea god Poseidon gave to Achilles’ father Peleus as a wedding gift, Xanthus and Balius, and the famous horse which Achilles stole from a city he attacked using his divine horses, Pedasos. According to legend, Achilles’ chariot is thought to been driven by three or four horses. Xanthus and Balius apparently served as the central pivot while Pedasos had a supporting role.
As divine horses received from Poseidon, Xanthus and Balius were clearly stated to have both been immortal in the original texts. After being summoned as a Servant’s Noble Phantasm, they aren’t quite immortal, but at the very least, they can be considered as tough as Servants themselves.
When Achilles is summoned as a Rider, his most harshly prana-consuming Noble Phantasm is this chariot. In the worst case, it is estimated that it can consume enough prana to summon another Servant besides Achilles.
Xanthus is a truly unpleasant horse who has fun telling Achilles when he falls into a dangerous situation.
- ↑ Fate/Grand Order material II - Asterios, pg.120-129
- ↑ Fate/Grand Order: Cosmos in the Lostbelt - Götterdämmerung: Eternal Ice-Flame Century, Chapter 6