Thetis. Thetis, is a figure from Greek mythology with varying mythological roles. She mainly appears as a sea nymph, a goddess of water, or one of the 50 Nereids, daughters of the ancient sea god Nereus. When described as a Nereid in Classical myths, Thetis was the daughter of Nereus and Doris, and a granddaughter of Tethys with whom she sometimes shares characteristics. Often she seems to lead the Nereids as they attend to her tasks. Sometimes she also is identified with Metis. Some sources argue that she was one of the earliest of deities worshipped in Archaic Greece, the oral traditions and records of which are lost. Only one written record, a fragment, exists attesting to her worship and an early Alcman hymn exists that identifies Thetis as the creator of the universe. Worship of Thetis as the goddess is documented to have persisted in some regions by historical writers such as Pausanias. In the Trojan War cycle of myth, the wedding of Thetis and the Greek hero Peleus is one of the precipitating events in the war which also led to the birth of their child Achilles. Most extant material about Thetis concerns her role as mother of Achilles, but there is some evidence that as the sea-goddess she played a more central role in the religious beliefs and practices of Archaic Greece. The pre-modern etymology of her name, from tithemi, to set up, establish, suggests a perception among Classical Greeks of an early political role. Walter Burkert considers her name a transformed doublet of Tethys. In Iliad I, Achilles recalls to his mother her role in defending, and thus legitimizing, the reign of Zeus against an incipient rebellion by three Olympians, each of whom has pre-Olympian roots: You alone of all the gods saved Zeus the Darkener of the Skies from an inglorious fate, when some of the other Olympians-Hera, Poseidon, and Pallas Athene-had plotted to throw him into chains. You, goddess, went and saved him from that indignity. You quickly summoned to high Olympus the monster of the hundred arms whom the gods call Briareus, but mankind Aegaeon, a giant more powerful even than his father. He squatted by the Son of Cronos with such a show of force that the blessed gods slunk off in terror, leaving Zeus free, E.V. Rieu translation Quintus of Smyrna, recalling this passage, does write that Thetis once released Zeus from chains; but there is no other reference to this rebellion among the Olympians, and some readers, such as M. M. Willcock, have understood the episode as an ad hoc invention of Homer's to support Achilles' request that his mother intervene with Zeus. Laura Slatkin explores the apparent contradiction, in that the immediate presentation of Thetis in the Iliad is as a helpless minor goddess overcome by grief and lamenting to her Nereid sisters, and links the goddess's present and past through her grief. She draws comparisons with Eos' role in another work of the epic Cycle concerning Troy, the lost Aethiopis, which presents a strikingly similar relationship-that of the divine Dawn, Eos, with her slain son Memnon; she supplements the parallels with images from the repertory of archaic vase-painters, where Eos and Thetis flank the symmetrically opposed heroes, Achilles and Memnon, with a theme that may have been derived from traditional epic songs. Thetis does not need to appeal to Zeus for immortality for her son, but snatches him away to the White Island Leuke in the Black Sea, an alternate Elysium where he has transcended death, and where an Achilles cult lingered into historic times. Pseudo-Apollodorus' Bibliotheke asserts that Thetis was courted by both Zeus and Poseidon, but she was married off to the mortal Peleus because of their fears about the prophecy by Themis that her son would become greater than his father. Thus, she is revealed as a figure of cosmic capacity, quite capable of unsettling the divine order. When Hephaestus was thrown from Olympus, whether cast out by Hera for his lameness or evicted by Zeus for taking Hera's side, the Oceanid Eurynome and the Nereid Thetis caught him and cared for him on the volcanic isle of Lemnos, while he labored for them as a smith, working there in the hollow of the cave, and the stream of Okeanos around us went on forever with its foam and its murmur. Thetis is not successful in her role protecting and nurturing a hero, but her role in succoring deities is emphatically repeated by Homer, in three Iliad episodes: as well as her rescue of Zeus and Hephaestus, Diomedes recalls that when Dionysus was expelled by Lycurgus with the Olympians' aid, he took refuge in the Erythraean Sea with Thetis in a bed of seaweed.