The Trident

The trident was forged for Poseidon by the Cyclopes during the war against the Titans, at the same time as Zeus's thunderbolt and Hades's helm of invisibility. Three weapons, three brothers, one division of the cosmos.

It is, in origin, a fishing spear. Mediterranean fishermen used three-pronged spears for exactly this purpose, which grounds the sea god's weapon in the ordinary work of the sea rather than in abstraction. Scaled to divine size it stirs storms, calms them, strikes water from bare rock, and shakes the ground — Poseidon's other title is Earth-Shaker, and earthquakes are struck with it.

It settles arguments. Contesting Athens against Athena, Poseidon drove it into the Acropolis and a saltwater spring appeared; Athena produced the olive tree, and the Athenians judged the olive more useful. The marks of the trident were still shown on the rock centuries later, which is the sort of physical evidence Greek sanctuaries specialised in.

It also has a Roman afterlife in the arena. The retiarius gladiator fought with a net and a trident, dressed as a fisherman, against an opponent armed as a fish — the sea god's weapon reduced to a costume in a blood sport.

The three prongs have attracted symbolic readings ever since: the three domains, the three brothers, the three states of water. None of these is in the Greek sources, which are content to let it be a very large fishing spear that causes earthquakes.