Orphic Hymn
XVI.
TO NEPTUNE.
The FUMIGATION from MYRRH

HEAR, Neptune, ruler of the sea profound,
Whose liquid grasp begirts the solid ground;
Who, at the bottom of the stormy main,
Dark and deep-bosom'd, hold'st thy wat'ry reign;
Thy awful hand the brazen trident bears,
And ocean's utmost bound, thy will reveres:
Thee I invoke, whose steeds the foam divide,
From whose dark locks the briny waters glide;
Whose voice loud founding thro' the roaring deep,
Drives all its billows, in a raging heap;
When fiercely riding thro' the boiling sea,
Thy hoarse command the trembling waves obey.
Earth shaking, dark-hair'd God, the liquid plains
(The third division) Fate to thee ordains,
'Tis thine, cærulian dæmon, to survey
Well pleas'd the monsters of the ocean play,
Confirm earth's basis, and with prosp'rous gales
Waft ships along, and swell the spacious sails;
Add gentle Peace, and fair-hair'd Health beside,
And pour abundance in a blameless tide.

Neptune (Latin: Neptūnus) was the god of water and the sea[1] in Roman mythology and religion. He is analogous with, but not identical to, the Greek god Poseidon. In the Greek-influenced tradition, Neptune was the brother of Jupiter and Pluto, each of them presiding over one of the three realms of the universe, Heaven, Earth and the Netherworld. Depictions of Neptune in Roman mosaics, especially those of North Africa, are influenced by Hellenistic conventions.[2]

Unlike the Greek Oceanus, titan of the world-ocean, Neptune was associated as well with fresh water. Georges Dumézil suggested[3] that for Latins, who were not a seafaring people, the primary identification of Neptune was with freshwater springs. Like Poseidon, Neptune was worshipped by the Romans also as a god of horses, under the name Neptunus Equester, a patron of horse-racing.[4]

Etymology

The etymology of Neptunus is unclear and disputed. The ancient grammarian Varro derived the name from nuptus i.e. covering (opertio), with a more or less explicit allusion to the nuptiae, marriage of Heaven and Earth.[5]

Among modern scholars P. Kretschmer proposed a derivation from IE *neptu-, moist substance;[6] but Dumezil remarked words deriving from root *nep are not attested in IE languages other than Vedic and Avestan. He proposed an etymology that brings together Neptunus with Vedic and Avestan theonyms Apam Napat, Apam Napá and Old Irish theonym Nechtan, all meaning descendant of the waters. By using the comparative approach the Indo-Iranian, Avestan and Irish figures would show common features with the Roman historicised legends about Neptune. Dumezil thence proposed to derive the nouns from IE root *nepot or *nept, descendant, siter's son.[7][8] R. Bloch supposed it might be an adjectival form in -no from *nuptu-, meaning "he who is moist".[9] More recently[when?] German scholar H. Petersmann proposed an etymology from IE rootstem *nebh related to clouds and foggs, plus suffix -tu denoting an abstract verbal noun, and adjectival suffix -no which refers to the domain of activity of a person or his prerogatives. IE root *nebh, having the original meaning of damp, wet, has given Sanskrit nábhah, Hittite nepis, Latin nubs, nebula, German nebel, Slavic nebo etc. The concept would be close to that expressed in the name of Greek god Όυράνος, derived from IE root *h2vórso-, to water, irrigate and *h2vorsó, the irrigator.[10][11] This etymology would be more in accord with Varro's.

A different etymology grounded in the legendary history of Latium and Etruria was proposed by Preller and Müller-Deeke: Etruscan Nethunus, Nethuns would be an adjectival form of toponym Nepe(t), Nepete (presently Nepi), town of the ager Faliscus near Falerii. The district was traditionally connected to the cult of the god: Messapus and Halesus, eponymous hero of Falerii, were believed to be his own sons. Messapus led the Falisci and others to war in the Aeneid.[12] Nepi and Falerii have been famed since antiquity for the excellent quality of the water of their springs, scattered in meadows.

Worship and theology

The theology of Neptune may only be reconstructed to some extent as since very early times he was identified with the Greek god Poseidon, as he is present already in the lectisternium of 399 BC.[13] Such an identification may well be grounded in the strict relationship between the Latin and Greek theologies of the two deities.[14] It has been argued that Indo-European people, having no direct knowledge of the sea as they originated from inland areas, reused the theology of a deity originally either chthonic or wielding power over inland freshwaters as the god of the sea.[15] This feature has been preserved particularly well in the case of Neptune who was definitely a god of springs, lakes and rivers before becoming also a god of the sea, as is testified by the numerous findings of inscriptions mentioning him in the proximity of such locations. Servius the grammarian also explicitly states Neptune is in charge of all the rivers, springs and waters.[16]

He may find a parallel in Irish god Nechtan, master of the well from which all the rivers of the world flow out and flow back to.

Poseidon on the other hand underwent the process of becoming the main god of the sea at a much earlier time, as is shown in the Iliad.[17]

In the earlier times it was the god Portunes or Fortunus who was thanked for naval victories, but Neptune supplanted him in this role by at least the first century BC when Sextus Pompeius called himself "son of Neptune."[18] For a time he was paired with Salacia, the goddess of the salt water.[19]

Neptune was also considered the legendary progenitor god of a Latin stock, the Faliscans, who called themselves Neptunia proles. In this respect he was the equivalent of Mars, Janus, Saturn and even Jupiter among Latin tribes. Salacia would represent the virile force of Neptune.[20]

Temples

Neptune had two temples in Rome. The first, built in 25 BC, stood near the Circus Flaminius, the Roman racetrack, and contained a famous sculpture of a marine group by Scopas.[25] The second, the Basilica Neptuni, was built on the Campus Martius and dedicated by Agrippa in honour of the naval victory of Actium.[26]

Sacrifices

Neptune is one of only three Roman gods to whom it was appropriate to offer the sacrifice of bulls, the other two being Apollo and Mars.[27] The wrong offering would require a piaculum if due to inadvertency or necessity. The type of the offering implies a stricter connection between the deity and the worldly realm.[28]

Fertility deity and divine ancestor

German scholar H. Petersmann has proposed a rather different interpretation of the theology of Neptune. Developing his understanding of the theonym as rooted in IE *nebh, he argues that the god would be an ancient deity of the cloudy and rainy sky in company with and opposition to Zeus/Jupiter, god of the clear bright sky. Similar to Caelus, he would be the father of all living beings on Earth through the fertilising power of rainwater. This hieros gamos of Neptune and Earth would be reflected in literarature, e.g. in Vergil Aen. V 14 pater Neptunus. The virile potency of Neptune would be represented by Salacia (derived from salax, salio in its original sense of salacious, lustful, desiring sexual intercourse, covering). Salacia would then represent the god's desire for intercourse with Earth, his virile generating potency manifesting itself in rainfall. While Salacia would denote the overcast sky, the other character of the god would be reflected by his other paredra Venilia, representing the clear sky dotted with clouds of good weather. The theonym Venilia would be rooted in a not attested adjective *venilis, from IE root *ven(h) meaning to love, desire, realised in Sanskrit vánati, vanóti, he loves, Old Island. vinr friend, German Wonne, Latin Venus, venia. Reminiscences of this double aspect of Neptune would be found in Catullus 31. 3: "uterque Neptunus".[42]

In Petersmann's conjecture, besides Zeus/Jupiter, (rooted in IE *dei(h) to shine, who originally represented the bright daylight of fine weather sky), the ancient Indo-Europeans venerated a god of heavenly damp or wet as the generator of life. This fact would be testified by Hittite theonyms nepišaš (D)IŠKURaš or nepišaš (D)Tarhunnaš "the lord of sky wet", that was revered as the sovereign of Earth and men.[43] Even though over time this function was transferred to Zeus/Jupiter who became also the sovereign of weather, reminiscences of the old function survived in literature: e.g. in Vergil Aen. V 13-14 reading: "Heu, quianam tanti cinxerunt aethera nimbi?/ quidve, pater Neptune, paras?": "Whow, why so many clouds surrounded the sky? What are you preparing, father Neptune?".[44] The indispensability of water for its fertilizing quality and its strict connexion to reproduction is universal knowledge.[45] Takács too points to the implicit sexual and fertility significance of both Salacia and Venilia on the grounds of the context of the cults of Neptune, of Varro's interpretation of Salacia as eager for sexual intercourse and of the connexion of Venilia with a nymph or Venus.

Müller-Deeke and Deeke had already interpreted the theology of Neptune as that of a divine ancestor of a Latin stock, namely the Faliscans, as the father of their founder heroes Messapus and Halesus. Sharing this same approach Fowler considered Salacia the personification of the virile potency that generated a Latin people, parallel with Mars, Saturn, Janus and even Jupiter among other Latins.[46]

Neptunus equestris

Poseidon was connected to the horse since the earliest times, well before any connection of him with the sea was attested, and may even have originally been conceived under equine form. Such a feature is a reflection of his own chtonic, violent, brutal nature as earth-quaker, as well as of the link of the horse with springs, i.e. underground water, and the psychopompous character inherent in this animal.[47]

There is no such direct connexion in Rome. Neptune does not show any direct equine character or linkage.

It was Roman god Consus who bore a connexion to horses: his underground altar was located in the valley of the Circus Maximus at the foot of the Palatine, the place of horse races. On the day of his summer festival (August 21), the Consualia aestiva, it was customary to bring in procession horses and mules crowned with flowers and then hold equine races in the Circus. It appears these games had a rustic character: they marked the end of the yearly agricultural cycle, when harvest was completed.[48] According to tradition this occasion was chosen to enact the abduction of the Sabine (and Latin) women. The episode might bear a reflection of the traditional sexual licence of such occasions.[49] On that day the flamen Quirinalis and the vestal virgins sacrificed on the underground altar of Consus. The fact the two festivals of Consus were followed after an equal interval of four days by the two festivals of Ops (Opeconsivia on August 25 and Opalia on December 19) testifies to the strict relationship between the two deities as pertaining to agricultural bounty, or in Dumezilian terminology to the third function. This fact shows the radically different symbolic value of the horse in the theology of Poseidon and that of Consus.

Perhaps under the influence of Poseidon Ίππιος Consus was reinterpreted as Neptunus equestris and for his underground altar also identified with Poseidon Ένοσίχθων. The archaic and arcane character of his cult, which required the unearthing of the altar, are signs of the great antiquity of this deity and of his chtonic character. He was certainly a deity of agrarian plenty and of fertility. Dumezil interprets its name as derived from condere hide, store as a verbal noun in -u parallel to Sancus and Janus, meaning god of stored grains.[50]

Martianus Capella places Neptune and Consus together in region X of Heaven: it might be that he followed an already old interpretatio graeca of Consus or he might be reflecting an Etruscan idea of a chthonic Neptune. Etruscans were particularly fond of horse races.[51]

From: Wiki

The Neptunalia was an obscure archaic two-day festival in honour of Neptune as god of waters, celebrated at Rome in the heat and drought of summer, probably July 23 (Varro, De lingua Latina vi.19). It was one of the dies comitiales, when committees of citizens could vote on civil or criminal matters. In the ancient calendar this day is marked as Nept. ludi et feriae, or Nept. ludi, from which Leonhard Schmitz (in Smith, see link) concluded that the festival was celebrated with games (ludi). Respecting the ceremonies of this festival nothing is known, except that the people used to build huts of branches and foliage (umbrae, according to Festus, under " Umbrae"), in which they probably feasted, drank, and amused themselves (Horace Carmina iii.28.1, &c.; Tertullian De Spectaculis ("On Celebrations") 6). Compare to the "booths" under which Jews celebrate Sukkot.

From: here
Myths about the Roman God Neptune
Neptune was the son of Saturn, and Rhea or Ops, and brother of Jupiter. When arrived at maturity, he assisted his brother Jupiter in his expeditions, for which that god, on attaining to supreme power, assigned him the sea and the islands for his empire. Whatever attachment Neptune might have had to his brother at one period, he was at another expelled heaven for entering into a conspiracy against him, in conjunction with several other deities; whence he fled, with Apollo, to Laomedon, king of Troy, where Neptune having assisted in raising the walls of the city, and being dismissed unrewarded, in revenge, sent a sea-monster to lay waste the country.

On another occasion, this deity had a contest with Vulcan and Minerva, in regard to their skill. The goddess, as a proof of her's, made a horse, Vulcan a man, and Neptune a bull, whence that animal was used in the sacrifices to him, though it is probable that, as the victim was to be black, the design was to point out the raging quality and fury of the sea, over which he presided. The Greeks make Neptune to have been the creator of the horse, which he produced from out of the earth with a blow of his trident, when disputing with Minerva who should give the name to Cecropia, which was afterwards called Athens, from the name in Greek of Minerva, who made an olive tree spring up suddenly, and thus obtained the victory.

In this fable, however, it is evident that the horse could signify nothing but a ship; for the two things in which that region excelled being ships and olive-trees, it was thought politic by this means to bring the citizens over from too great a fondness for sea affairs, to the cultivation of their country, by showing that Pallas was preferable to Neptune, or, in other words, husbandry to sailing, which, without some further meaning, the production of a horse could never have done. It notwithstanding appears that Neptune had brought the management of the horse, as likewise the art of building ships, to very great perfection; insomuch that Pamphus, who was the most ancient writer of hymns to the gods, calls him the benefactor of mankind, in bestowing upon them horses and ships which had stems and decks that resembled towers.

If Neptune created the horse, he was likewise the inventor of chariot-races; hence Mithridates, king of Pontus, threw chariots, drawn by four horses, into the sea, in honor of Neptune: and the Romans instituted horse-races in the circus during his festival, at which time all horses ceased from working, and the mules were adorned with wreaths of flowers.

Neptune, represented as a god of the sea, makes a considerable figure: he is described with black or dark hair, his garment of an azure or sea-green color, seated in a large shell drawn by whales, or sea-horses, with his trident in his hand, attended by the sea-gods PalAemon, Glaucus, and Phorcys; the sea-goddesses Thetis, Melita, and Panopea, and a long train of Tritons and sea-nymphs.

The inferior artists represent him sometimes with an angry and disturbed air; and we may observe the same difference in this particular between the great and inferior poets as there is between the bad and the good artists. Thus Ovid describes Neptune with a sullen look, whereas Virgil expressly tells us that he has a mild face, even where he is representing him in a passion. Even at the time that he is provoked, and might be expected to have appeared disturbed, and in a passion, there is serenity and majesty in his face.

On some medals he treads on the beak of a ship, to show that he presided over the seas, or more particularly over the Mediterranean sea, which was the great, and almost the only scene for navigation among the old Greeks and Romans. He is standing, as he generally was represented; he most commonly, too, has his trident in his right hand: this was his peculiar sceptre, and seems to have been used by him chiefly to rouse up the waters; for we find sometimes that he lays it aside when he is to appease them, but he resumes it when there is occasion for violence. Virgil makes him shake Troy from its foundation with it; and in Ovid it is with the stroke of this that the waters of the earth are let loose for the general deluge. The poets have generally delighted in describing this god as passing over the calm surface of the waters, in his chariot drawn by sea-horses. The fine original description of this is in Homer, from whom Virgil and Statius have copied it.

In searching for the mythological sense of the fable, we must again have recourse to Egypt, that kingdom which, above all others, has furnished the most ample harvest for the reaper of mysteries. The Egyptians, to denote navigation, and the return of the Phoenician fleet, which annually visited their coast, used the figure of an Osiris borne on a winged horse, and holding a three-forked spear, or harpoon. To this image they gave the name of Poseidon, or Neptune, which, as the Greeks and Romans afterwards adopted, sufficiently proves this deity had his birth here. Thus the maritime Osiris of the Egyptians became a new deity with those who knew not the meaning of the symbol.

From: here
Neptune was originally the minor god of fresh water and irrigation.

It wasn't until the Romans identified him with Greek Poseidon (399 BC), that he became the great god of the sea. His consort was Salacia (possibly Amphitrite). Neptune was also equated with Nethuns, the Etruscan god of fresh water and well.

His festival, Neptunalia, was held on July 23, and his temple was found in Circus Flamminius, Rome.

In astronomy, the 8th planet from the sun, and the 4th largest planet in our solar system. The planet is blue in colour, due to high concentration of methane gas in its atmosphere; as well as hydrogen and helium. Like the other giant planets, it has rings. There are at least eight satellites in Neptune's orbit; the largest moons are Triton and Nereid.

From: here
Alternate Names/Spellings: Netpunus, Saturnius ("son of Saturn")

Neptune is the god of water, rain, and fertility. Later he also became a god of horses. Neptune is often associated with Poseidon and Consus. His consort is either Salacia or Venilia. Bulls were a proper sacrifice for Neptune. His sacred stones are beryl and pearl.

Festivals for Neptune were held on July 23th (the Neptunalia) and December 1st.

From: here
Before Neptune there was the Hellenistic god Poseidon, one of the three senior gods, brother of Zeus and Hades. When the world was divided between these three, by lot, Zeus received the earth, Hades the underworld, and Poseidon became lord of the sea. He was also known as the earth-shaker, creator of earthquakes.

He appeared on many Hellenistic coins, including the bronze of Macedonia on the right. As a senior deity, he was shown mature and bearded. He always carried a trident, and it is over his shoulder on this coin. In fact the trident often appeared alone, as his symbol, as on the coin on the far right from Corinth, where he was the chief deity of the city.

In Athens, he came second to Athena in a contest to see who the city would accept as its patron. The salty spring he produced was far less useful than Athena's olive tree. His conflict with Athena also appeared in the myth of Medusa. He ravished the then beautiful Medusa in the grounds of Athena's temple, which aroused her to anger and caused her to curse Medusa with ugliness and deadliness. You may think that this was not very fair to Medusa, but fairness is not a distinguishing feature of Greek myths.
The obverse of a fake Roman Republican denarius of showing Neptune The obverse of a fake Roman Republican denarius of showing Neptune.

The Romans developed a deity they called Neptune, who seems to have evolved from the Etruscan god Nethuns. Both of these were close equivalents of the Hellenistic Poseidon, but as usual with the Roman pantheon, not completely identical. A temple to Neptune was built in Rome in 25 BCE, near the Circus Flaminius, a multi-purpose venue south of the Field of Mars. He had a two-day festival of obscure and archaic origins, called Neptunalia, on which tents or huts were made from foliage and the branches of bushes.

On the left is a (modern copy of) a Roman Republican denarius of Sextus Pompey, 100 to 150 years later than the Macedonian coin above, but with an almost identical image. Sextus Pompeius Magnus Pius was the youngest son of the famous Pompey the Great, who fought unsuccessfully against Julius Caesar.

The youngest Pompey also fought Caesar, and later retreated to Sicily, where for many years he had a successful base. This denarius may have been struck to celebrate a naval victory over Augustus. By this time, Neptune was established as the deity to be thanked for naval victories. In fact, Sextus Pompey called himself "son of Neptune."

For the rest see link.
From: Neptune, the Sea God
Various prayers:
1.188-203: Neptune, Lord of Waters, the highest honor falls to You, along the shoreline, decked with dark blue ribbons, a bull Ancaeus fells, and to Zephyris and Glaucus bulls as well, while a heifer is offered to Thetis.No one is more deft than he with the ritual axe at the fat necks of the cattle.Jason himself pours a goblet in libation to the lord of the sea, saying, "O god, who with a nod can stir the ocean foam, You who with Your salt water encompass the lands of the earth, hear my prayer and grant me Your indulgence.I am the first of mankind to venture forth on unlawful paths across Your waters, and therefore, one might suppose, deserve the worst of Your storms.It is not my own idea to presume in this way, to pile mountain on high mountain and summon down from Olympus bolts of heavenly lightning.Pelias’ prayers are false.Do not be swayed by his vows, but know that he devised and imposed his cruel commands to send me off to Colchis and bring on me and my kin the bitterest grief.I beg of You, therefore, mercy and justice.Let Your waters receive me: bear me up and protect this ship and its crew of kings."Thus he spoke as he poured the rich wine from the cup on the blazing coals of fire.

tum laeti statuunt aras. tibi, rector aquarum, / summus honor, tibi caeruleis in litore vittis / et Zephyris Glaucoque bovem Thetidique iuvencam / deicit Ancaeus:non illo certior alter / pinguia letifera perfringere colla bipenni / .ipse ter aequoreo libans carchesia patri / sic ait Aesonides: 'o qui spumantia nutu / regna quatis terrasque salo complecteris omnes, / da veniam! scio me cunctis e gentibus unum / inlicitas temptare vias hiememque mereri: /sed non sponte feror nec nunc mihi iungere montes / mens ~tamen~ aut summo deposcere fulmen Olympo / ne Peliae te vota trahant! ille aspera iussa / repperit et Colchos in me luctumque meorum / illum ego--tu tantum non indignantibus undis / hoc caput accipias et pressam regibus alnum.'


Argonautica: Prayers of G. Valerius Flaccus
From: here
Carminum Liber I v
(O Neptune)
...stare in wondering shock
At winds gone wild on blackening seas!
...how false the breeze can blow.
Pity all those who have not found out
Your glossy sweetness! My shipwreck's tale
Hangs, told in colours, on Neptune's temple wall, a votive
Plaque, with salvaged clothes
Still damp, vowed to the sea's rough lord.
From: here
Father and Master of the mighty Deep, look, Neptune, at what kind of pitiful use You allow passage across the open seas. Safely under sail pass the crimes of nations, ever since that Pagasean prow ruptured the sanctions of law and the hallowed dignity of the sea while carrying Jason in his quest for plunder. Grant that I may drive off mourning, and that it not be pleasing to You that over so many waves I should find but a single shore to inhabit a sepulcher on some Ilian promontory.

(...)

Gods, who delight in preserving bold ships and turning from them the perils of windy seas, make smooth and placid these waters, and attend with good council my vows, let not my words be drowned out by roaring waves as I pray:

O Neptune, grand and rare is the pledge we make to You, and in what we commend into the depths of the sea. Young Maecius it is whose body we commit to the sea, far from the sight of land, that he, the better part of our souls, traverses the sea’s length and depth (to the Western Lands.

Bring forth the benign stars, the Spartan brothers, Castor and Pollux, to sit upon the horns of the yard arm. Let your light illuminate sea and sky. Drive off your sister Helen’s stormy star, I pray, and expel it from all the heavens.

And you azure Nereids of the seas, whose good fortune it was to attain mastery of the oceans may it be allowed to name you stars of the seas rise up from your glassy caverns near the foaming waves that encircle Doris, and tranquilly swim circles around the shores of Baiae where the hot springs abound. Seek after the lofty ship on which a noble descendant of Ausonians, Celer, mighty at arms, is glad to embark. Not long will you need to look, for she lately came across the sea, leading a convoy laden with Egyptian wheat and bound for Dicarcheis. First was she to salute Capreae and from her starboard side offer a libation of Mareotic wine to Tyrrhenian Minerva. Near to her, on either side, circle gracefully around her. Divide your labors, some to tighten fast the rigging from masts to deck, while others high above spread forth canvass sails to the westerly Zephyrs. Still others replace some benches, others send into the water the rudder by whose curved blade steers the ship. Another plumbs the depths with leaden weights while others to fasten the skiff that follows astern, and to dive down and drag the hooked anchor from the depths, and one to control the tides and make the sea flow eastward. Let none of the sea green sisterhood be without her task.

Then let Proteus of manifold shape and triformed Triton swim before, and Glaucus whose loins vanished by sudden enchantment, and who, so oft as he glides up to his native shores, wistfully beats his fish tail on Anthedon’s strand.

But above all others you, Palaemon, with your goddess mother, be favourable, if I have a passion to tell of your own Thebes, and sing of Amphion, bard of Phoebus, with no unworthy quill.

And may the father whose Aeolian prison constrains the winds, whom the various blasts obey, and every air that stirs on the world’s seas, and storms and cloudy tempests, keep the North wind and South and East in closer custody behind his wall of mountain, but may Zephyr alone have the freedom of the sky, alone drive vessels onward and skim unceasingly over the crests of billows, until he brings without a storm your glad sails safe to the Paraetonian haven.

From: here

Also see:
Neptunalia article
short summary
Modern hymn to him

On MW:
Poseidon - Ποσειδῶν {God of the Week}