Thetis was not one of the major goddesses of the Greek pantheon. Considering her status, her impact on mythology was oversized.
The one-time fiancee of Zeus was a protective goddess who saved the lives of many Olympic gods. According to Homer, one of these was Zeus himself.
Her wedding feast as a joyous occasion, but the exclusion of Eris from the guest list led to the beginning of the Trojan War and Thetis’s greatest personal tragedy.
Her influence was so great that she was able to convince Zeus, the famously rigid king of the gods, to change his mind in her favor. While it did not save her son’s life, the story of Zeus and Thetis does show that the protective Nereid may have once been more than she seemed.
Thetis is usually seen as a fairly minor goddess in Greek mythology, but one whose life was intertwined with many major events.
Thetis was usually described as a water goddess, often a Nereid. She was also meant to be Zeus’s second wife.
Zeus married the Titaness Metis, but swallowed her when he learned that she would one day have a son who would overthrow him. Shortly afterward, he began to be interested in Thetis.
Before he could act on this attraction, however, he heard a similar prophecy regarding his new paramour. Thetis, too, was fated to one day give birth to a son who would be more powerful and famous than his father.
Zeus did not want to risk following in the footsteps of both his father and grandfather by being violently overthrown. To maintain his power, he abandoned Thetis and married Hera instead.
Thetis ended up not become the mother of Zeus’s child, but the foster mother of Hera’s. She and the ocean nymphs found Hephaestus when he was cast down from Olympus and raised him on earth.
Many times, Thetis came to the rescue of the gods. When Dionysus was expelled from Thrace, for example, Thetis hid him in a bed of seaweed.
She was most famous, however, for her role in human affairs rather than those of the gods.
Zeus eventually determined that the prophecy surrounding Thetis was too dangerous for any of the gods to risk marrying her. Instead, he arranged for her to be married to a mortal man.
Peleus was a great hero and because Thetis was well-loved by the Olympians the wedding was among the most elaborate feasts ever held on Mount Olympus. The only goddess who was not invited was Eris, the personification of discord.
The exclusion of the goddess of strife from the wedding prompted her to seek revenge on the Olympians for slighting her. She sent a golden apple addressed to the fairest goddess of Olympus and the resulting infighting among the goddesses helped to ignite the Trojan War.
Her involvement in the war went beyond its beginnings, however. Thetis became heavily involved in the conflict because her son with Peleus, Achilles, was one of the fighters.
Thetis attempted to protect her son by burning away his mortality, but Peleus stopped her because he believed she was hurting the baby. According to some legends, Achilles was left with a single vulnerability on the heel where his mother had held him.
Throughout the war, Thetis attempted to intervene to keep her son safe. She even went directly to Zeus to ask him to intercede on behalf of Achilles.
Homer’s Iliad is the only source that includes the leverage a minor goddess could use to sway the will of the king of the gods. According to the poet, the gods of Olympus had once rebelled against Zeus and Thetis had been the one to save him.
Hera, Poseidon, and Athena had put the king of the gods in chains in an attempted coup. Thetis had summoned a hundred-armed giant to break the chains and restore Zeus to power.
Homer may have believed that Zeus owed his throne to Thetis, but her requests did little good. As a prophecy had foretold, her son lived a short but glorious life and fell in battle during the Trojan War.
Thetis was unusual for the nymphs in the major role she played in shaping the outcome of many myths. She rescued many gods, mothered a great hero, nearly married the king of Olympus, and her marriage directly led to the beginning of the Trojan War.
Some historians see this role as evidence that Thetis was once a more powerful goddess in a pre-classical tradition.
It is possible that Thetis was a double of Tethys, the Titan goddess of the sea. The two may have once been the same entity, but developed separate mythologies and names over time.
The story of her engagement to Peleus also has aspects of more ancient sea gods. Like The Old Man of the Sea, Thetis was a shapshifter who could only be captured by someone able to hold on as she turned into a variety of bestial and monstrous creatures.
That would explain how Thetis was more prominent and powerful than most other nymphs, but her interactions with Zeus also show that she may have held greater power in the pre-literate past.
Her most prominent role is in the works of Homer, who was also one of the first poets to write down the Greek legends. Because of the style in which he wrote and his early date, Homer’s poems often seem to reflect older versions of well-known stories.
In the Iliad, Thetis is a powerful enough goddess to bend Zeus to her will. When she makes a request of the king of the gods, he changes his position to please her.
Homer attributes this in part to the fact that Thetis had saved his life and throne. Just as Metis had helped him defeat Cronus, Thetis helped him hold on to power.
The parallels between these suggest that this may have been a motif throughout the early Greek world. Different traditions existed of Zeus marrying, then discarding, an older goddess who had given him aid but whose son would be a threat to him.
In the Iliad Thetis had to go to Zeus to ask for her son to be protected. While Homer showed Thetis in a central role, this seems contrary to her appearances in other stories.
Thetis was consistently portrayed as a savior of the gods. On at least three occasions she protected or nursed one of the Olympians when they were at their most vulnerable.
This may indicate that in earlier myths Thetis was a protective goddess. By the time of Homer she was still well-regarded, but her position had declined enough that she had to ask Zeus for protection instead of providing it herself.
Thetis was meant to be the second wife of Zeus, but the engagement was abandoned when he learned that her son would one day be more powerful than his father.
To prevent the threat to any of the other gods, he had Thetis married to a human. Peleus was a heroic general, but his fame was far surpassed by their son, Achilles.
Thetis was usually cast in the role of a protective goddess, which could be a holdover from an earlier belief system. At least three stories describe her sheltering or freeing vulnerable Olympians.
She was not successful, however, in protecting her own son. Achilles died in the final days of the Trojan War despite his mother’s attempts to shield him from harm.
Thetis had even gone so far as to implore Zeus for aid, showing herself to be one of the few deities who could turn the god’s opinion in her favor. Homer alone explains that this deference was because Thetis had once freed the king of the gods when the other members of his family had attempted a rebellion.
The interactions between Thetis and Zeus seem to show that she was once a more powerful goddess of protection than she was later believed to be. Before the time of Homer, it was Zeus who asked for aid from Thetis instead of the other way around.