Trophonius, Historia Deo­rum Fatidi­co­rum, Geneva 1675

Tro­pho­nius (the Lati­nate spelling) or Tro­pho­nios (Τροφώνιος) (in the translit­er­ated Greek spelling) was a Greek hero or dai­mon or god  it was never cer­tain which one  with a rich mytho­log­i­cal tra­di­tion and an orac­u­lar cult at Leva­dia in Viotia.

Ety­mol­ogy and par­al­lel cults

The name is ety­mo­log­i­cally derived from trepho, «to nour­ish». Strabo and sev­eral inscrip­tions refer to him as Zeus Tre­pho­nios. Sev­eral other chthonic Zeuses with sim­i­lar titles are known from the Greek world, includ­ing Zeus Mei­likhios («hon­eyed» or «kindly» Zeus), and Zeus Chtho­nios («Zeus beneath-the-earth»). Similar con­struc­tions are also found in the Roman world: for exam­ple, a shrine at Lavinium in Lazio was ded­i­cated to Aeneas under the title Iup­piter Indi­ges (Jupiter in  the earth).

Tro­pho­nius in myth

In Greek mythol­ogy, Tro­pho­nius was a son of Ergi­nus. Accord­ing to the Home­ric Hymn to Apollo, he built Apollos tem­ple at the ora­cle at Del­phi with his brother, Agamedes. Once fin­ished, the ora­cle told the broth­ers to do what­so­ever they wished for six days and, on the sev­enth, their great­est wish would be granted. They did and were found dead on the sev­enth day. The say­ing «those whom the gods love die young» comes from this story.
Alter­na­tively, accord­ing to Pau­sa­nias they built a trea­sure cham­ber (with secret entrance only they knew about) for King Hyprieus of Vio­tia. Using the secret entrance, they stole Hyprieus» for­tune. He was aware but did not know who the thief was; he laid a snare. Agamedes was trapped in it; Tro­pho­nius cut off his head so that Hyprieus would not know who the body in the snare was. He then fled into the cav­ern at Leva­dia, and dis­ap­peared forever.
The cave of Tro­pho­nius was not dis­cov­ered again until the Leva­di­ans suf­fered a plague, and con­sulted the Del­phic Ora­cle. The Pythia advised them that an unnamed hero was angry at being neglected, and that they should find his grave and offer him wor­ship forth­with. Sev­eral unsuc­cess­ful searches fol­lowed, and the plague con­tin­ued unabated until a shep­herd boy fol­lowed a trail of bees into a hole in the ground. Instead of honey, he found a dai­mon, and Leva­dia lost its plague while gain­ing a pop­u­lar oracle.
The child­less Xuthus in Euripides Ion con­sult Tro­pho­nius on his way to Del­phi.
Apol­lo­nius of Tyana, a leg­endary wise man and seer of Late Antiq­uity, once vis­ited the shrine and found that, when it came to phi­los­o­phy, Tro­pho­nius was a pro­po­nent of sound Pythagorean doctrines.
Plutarch’s De Genio Socratis relates an elab­o­rate dream-?vision con­cern­ing the cos­mos and the after­life that was sup­pos­edly received at Trophonius oracle.

Tro­pho­nius in cult
Pau­sa­nias, in his account of Vio­tia (9.39), relates many details about the cult of Tro­pho­nius. Who­ever desired to con­sult the ora­cle would live in a des­ig­nated house for a period of days, bathing in the river Herkyna and liv­ing on sac­ri­fi­cial meat. He would then sac­ri­fice, by day, to a series of gods, includ­ing Kro­nos, Apollo, Zeus the king, Hera the Char­i­o­teer, and Demeter- Europa. At night, he would a black vic­tim into a pit sacred to Agamedes, drink from two rivers called Lethe and Mnemosyne, and then descend into a cave. Here, most con­sul­tees were fright­ened out of their wits, and for­got the expe­ri­ence entirely upon com­ing up.Afterward, the con­sul­tee would be seated upon a chair of Mnemosyne, where the priests of the shrine would record his rav­ings and com­pose an ora­cle out of them.

Tro­pho­nius in the clas­si­cal tradition

«To descend into the cave of Tro­pho­nios» became a prover­bial way of say­ing «to suf­fer a great fright»: this say­ing is alluded to in Aristophanes Clouds. Sev­eral ancient philoso­phers, includ­ing Her­a­clides Pon­ti­cus, wrote com­men­taries on the cult of Tro­pho­nios that are now sadly lost.

Tro­pho­nios has been of inter­est to clas­si­cal schol­ars because the rivers of Letheand Mnemosyne have close par­al­lels with the Myth of Er at the end of Platos Repub­lic, with a series of Orphic funer­ary inscrip­tions on gold leaves, and with sev­eral pas­sages about Mem­ory and for­get­ting in Hesiod’s Theogony.

Her­cyna (gr. Herkyna) in Greek Mythol­ogy was a Naiad asso­ci­ated with the Herkyna river of Viotia.

Ora­cle of Tro­pho­nius at Lebadeia in Vio­tia (Paus. IX.37 §3). Those who wished to con­sult this ora­cle had first to purify them­selves by spend­ing some days in the sanc­tu­ary of the good spirit and good luck  to live sober and pure, to abstain from warm baths, but to bathe in the river Her­cyna, to offer sac­ri­fices to Tro­pho­nius and his chil­dren, to Apollo, Cronos, king Zeus, Hera Heniocha, and to Deme­ter Europe, who was said to have nursed Tro­pho­nius and dur­ing these sac­ri­fices a sooth­sayer explained from the intestines of the vic­tims whether Tro­pho­nius would be pleased to admit the con­sul­tor. In the night in which the con­sul­tor was to be allowed to descend into the cave of Tro­pho­nius, he had to sac­ri­fice a ram to Agamedes, and only in case the signs of the sac­ri­fice were favourable, the hero was thought to be pleased to admit the per­son into his cave. What took place after this was as fol­lows: Two boys, 13 years old, led him again to the river Her­cyna, and bathed and anointed him. The priests then made him drink from the well of obliv­ion (Λήθη) that he might for­get all his for­mer thoughts, and from the well of rec­ol­lec­tion (Μνημοσύνη) that he might remem­ber the visions which he was going to have. They then showed him a mys­te­ri­ous rep­re­sen­ta­tion of Tro­pho­nius, made him wor­ship it, and led him into the sanc­tu­ary, dressed in linen gar­ments with gir­dles around his body, and wear­ing a pecu­liar kind of shoes  which were cus­tom­ary at Lebadeia. Within the sanc­tu­ary which stood on an emi­nence, there was a cave, into which the per­son was now allowed to descend by means of a lad­der. Close to the bot­tom, in the side of the cave, there was an open­ing into which he put his feet, where­upon the other parts of the body were like­wise drawn into the open­ing by some invis­i­ble power. What the per­sons here saw was dif­fer­ent at dif­fer­ent times. They returned through the same open­ing by which they had entered, and the priests now placed them on the throne of Mnemosyne, asked them what they had seen, and led them back to the sanc­tu­ary of the good spirit and good luck. As soon as they had recov­ered from their fear, they were obliged to write down their vision on a lit­tle tablet which was ded­i­cated in the tem­ple. This is the account given by Pau­sa­nias, who had him­self descended into the cave, and writes as an eye-witness (Paus. IX.39 §3, &c.; com­pare Philostr. Vit. Apoll. viii.19). The answers were prob­a­bly given by the priests accord­ing to the report of what per­sons had seen in the cave. This ora­cle was held in very great esteem, and did not become extinct until a very late period: and though the army of Sulla had plun­dered the tem­ple, the ora­cle was much con­sulted by the Romans (Orig. c. Cels. vii p355), and in the time of Plutarch it was the only one among the numer­ous Viot­ian ora­cles, that had not become silent (Plut. de Orac. Def. c5).

At Liva­dia they remained the greater part of three days, dur­ing which they exam­ined with more than ordi­nary minute­ness the cave of Tro­pho­nius, and the streams of the Her­cyna, com­posed of the min­gled waters of the two foun­tains of Obliv­ion and Mem­ory. Lord Byron in Greece.