The name as well as the nature of this divinity is one of the most difficult points in ancient mythology. Some consider Rhea to be merely another form of era, the earth, while others connect it with rheô, I flow (Plat. Cratyl. p. 401, &c.); but thus much seems undeniable, that Rhea, like Demeter, was a goddess of the earth. According to the Hesiodic Theogony (133; comp. Apollod. i. 1. § 3), Rhea was a daughter of Uranus and Ge, and accordingly a sister of Oceanus, Coeus, Hyperion, Crius, Iapetus, Theia, Themis, and Mnemosyne. She became by Cronos the mother of Hestia, Demeter, Hera, Aides, Poseidon, and Zeus. According to some accounts Cronos and Rhea were preceded in their sovereignty over the world by Ophion and Eurynome ; but Ophion was overpowered by Cronos, and Rhea cast Eurynome into Tartarus. Cronos is said to have devoured all his children by Rhea, but when she was on the point of giving birth to Zeus, she, by the advice of her parents, went to Lyctus in Crete. When Zeus was born she gave to Cronos a stone wrapped up like an infant, and the god swallowed it as he had swallowed his other children. (Hes. Theog. 446, &c.; Apollod. i. 1. § 5, &c.; Diod. v. 70.) Homer (Il. xv. 187) makes only a passing allusion to Rhea, and the passage of Hesiod, which accordingly must be regarded as the most ancient Greek legend about Rhea, seems to suggest that the mystic priests of Crete had already formed connections with the more northern parts of Greece. In this manner, it would seem, the mother of Zeus became known to the Thracians, with whom she became a divinity of far greater importance than she had been before in the south (Orph. Hymn. 13, 25, 26), for she was connected with the Thracian goddess Bendis or Cotys (Hecate), and identified with Demeter. (Strab. x. p. 470.)
The Thracians, in the mean time, conceived the chief divinity of the Samothracian and Lemnian mysteries as Rhea-Hecate, while some of them who had settled in Asia Minor, became there acquainted with still stranger beings, and one especially who was worshipped with wild and enthusiastic solemnities, was found to resemble Rhea. In like manner the Greeks who afterwards settled in Asia identified the Asiatic goddess with Rhea, with whose worship they had long been familiar (Strab. x. p. 471; Hom. Hymn. 13, 31). In Phrygia, where Rhea became identified with Cybele, she is said to have purified Dionysus, and to have taught him the mysteries (Apollod. iii. 5. § 1), and thus a Dionysiac element became amalgamated with the worship of Rhea. Demeter, moreover, the daughter of Rhea, is sometimes mentioned with all the attributes belonging to Rhea. (Eurip. Helen. 1304.) The confusion then became so great that the worship of the Cretan Rhea was confounded with that of the Phrygian mother of the gods, and that the orgies of Dionysus became interwoven with those of Cybele. Strangers from Asia, who must be looked upon as jugglers, introduced a variety of novel rites, which were fondly received, especially by the populace (Strab. 1. c.; Athen. xii. p. 553 ; Demosth. de Coron. p. 313). Both the name and the connection of Rhea with Demeter suggest that she was in early times revered as goddess of the earth.
Crete was undoubtedly the earliest seat of the worship of Rhea; Diodorus (v. 66) saw the site where her temple had once stood, in the neighbourhood of Cnossus, and it would seem that at one time she was worshipped in that island even under the name of Cybele (Euseb. Chron. p. 56; Syncell. Chronogr. p. 125). The common tradition, further, was that Zeus was born in Crete, either on Mount Dicte or Mount Ida. At Delphi there was a stone of not very large dimensions, which was every day anointed with oil, and on solemn occasions was wrapped up in white wool; and this stone was believed to have been the one which Cronos swallowed when he thought he was devouring Zeus (Paus. x. 24. § 5). Such local traditions implying that Rhea gave birth to Zeus in this or that place of Greece itself occur in various other localities. Some expressly stated that he was born at Thebes (Tzetz. ad Lyc. 1194). The temple of the Dindymenian mother had been built by Pindarus (Paus. ix. 25. § 3; Philostr. Icon. ii. 12). Another legend stated that Rhea gave birth at Chaeroneia in Boeotia (Paus. ix. 41. § 3), and in a temple of Zeus at Plataeae Rhea was represented in the act of handing the stone covered in cloth to Cronos (Paus. ix. 2. § 5). At Athens there was a temple of Rhea in the peribolos of the Olympieium (Paus. i. 18. § 7), and the Athenians are even said to have been the first among the Greeks who adopted the worship of the mother of the gods (Julian, Orat. 5). Her temple there was called the Metroum. The Arcadians also related that Zeus was born in their country, on Mount Lycaon, the principal seat of Arcadian religion (Paus. viii. 36. § 2, 41. § 2; comp. Callim. Hymn. in Jov. 10, 16, &c.). Similar traces are found in Messenia (Paus. iv. 33. § 2), Laconia (iii. 22. § 4), in Mysia (Strab. xiii. p. 589), at Cyzicus (i. p. 45, xii. p. 575). Under the name of Cybele, we find her worship on Mount Sipylus (Paus. v. 13. § 4), Mount Coddinus (iii. 22. § 4), in Phrygia, which had received its colonists from Thrace, and where she was regarded as the mother of Sabazius. There her worship was quite universal, for there is scarcely a town in Phrygia on the coins of which she does not appear. In Galatia she was chiefly worshipped at Pessinus, where her sacred image was believed to have fallen from heaven (Herodian, i. 35). King Midas I. built a temple to her, and introduced festive solemnities, and subsequently a more magnificent one was erected by one of the Attali. Her name at Pessinus was Agdistis (Strab. xii. p. 567). Her priests at Pessinus seem from the earliest times to have been, in some respects, the rulers of the place, and to have derived the greatest possible advantages from their priestly functions. Even after the image of the goddess was carried from Pessinus to Rome, Pessinus still continued to be looked upon as the metropolis of the great goddess, and as the principal seat of her worship. Under different names we might trace the worship of Rhea even much further east, as far as the Euphrates and even Bactriana. She was, in fact, the great goddess of the Eastern world, and we find her worshipped there in a variety of forms and under a variety of names. As regards the Romans, they had from the earliest times worshipped Jupiter and his mother Ops, the wife of Saturn. When, therefore, we read (Liv. xxix. 11, 14) that, during the Hannibalian war, they fetched the image of the mother of the gods from Pessinus, we must understand that the worship then introduced was quite foreign to them, and either maintained itself as distinct from the worship of Ops, or became united with it. A temple was built to her on the Palatine, and the Roman matrons honoured her with the festival of the Megalesia. The manner in which she was represented in works of art was the same as in Greece, and her castrated priests were called Galli.
The various names by which we find Rhea designated, are, "the great mother," "the mother of the gods," Cybele, Cybebe, Agdistis, Berecyntia, Brimo, Dindymene, "the great Idaean mother of the gods." Her children by Cronos are enumerated by Hesiod : under the name of Cybele she is also called the mother of Alce, of the Phrygian king Midas, and of Nicaea (Diod. iii. 57; Phot. Cod. 224). In all European countries Rhea was conceived to be accompanied by the Curetes, who are inseparably connected with the birth and bringing up of Zeus in Crete, and in Phrygia by the Corybantes, Atys, and Agdistis. The Corybantes were her enthusiastic priests, who with drums, cymbals, horns, and in full armour, performed their orgiastic dances in the forests and on the mountains of Phrygia. The lion was sacred to the mother of the gods, because she was the divinity of the earth, and because the lion is the strongest and most important of all animals on earth, in addition to which it was believed that the countries in which the goddess was worshipped, abounded in lions (comp. Ov. Met. x. 682). In Greece the oak was sacred to Rhea (Schol. ad Apollon. Rhod. i. 1124). The highest ideal of Rhea in works of art was produced by Pheidias; she was seldom represented in a standing posture, but generally seated on a throne, adorned with the mural crown, from which a veil hangs down. Lions usually appear crouching on the right and left of her throne, and sometimes she is seen riding in a chariot drawn by lions. (Comp. CURETES; ZEUS; CRONOS.)