The names Aurvandil or Earendel (Old Norse: Aurvandil; Old English: Ēarendel; Lombardic: Auriwandalo; Old High German: Orentil, Erentil; Medieval Latin: Horuuendillus) are cognate Germanic personal names, continuing a Proto-Germanic reconstructed compound *auzi-wandilaz "luminous wanderer", in origin probably the name of a star or planet, potentially the morning star (Eosphoros). Recall that also the word 'planet' means wanderer.
As a Germanic name, Auriwandalo is attested as a historical Lombardic prince. A Latinized version, Horvandillus, is given as the name of the father of Amleth in Saxo Grammaticus' Gesta Danorum. German Orentil (Erentil) is the hero of a medieval poem of the same name. He is son of a certain Eigel of Trier and has numerous adventures in the Holy Land.
The Old Norse variant appears in purely mythological context, linking the name to a star. The only known attestation of the Old English Earendel refers to a star exclusively.
The name is a compound whose first part goes back to *auzi- ‘dawn’, a combining form related to *austaz ‘east’, cognate with Ancient Greek ēṓs ‘dawn’, Sanskrit uṣā́s, Latin aurōra, ultimately from Proto-Indo-European *h₂éuso-s ‘dawn’. The second part comes from *wanđilaz, a derivative of *wanđaz (cf. Old Norse vandr ‘difficult’, Old Saxon wand ‘fluctuating, variable’, English wander), from *wenđanan which gave in English wend.
Jacob Grimm (1835) emphasizes the great age of the tradition reflected in the mythological material surrounding this name, without being able to reconstruct the characteristics of the Common Germanic myth. Viktor Rydberg in his Teutonic Mythology also assumes Common Germanic age for the figure.
The epic poem about a king Orendel or Erentel is preserved in the Heldenbuch tradition. King Erentel, son of Eigel is rescued at sea by a mysterious fisherman, Eisen. Erentel goes on to take the fisherman's magical coat, and his wife Breide.
Chronicon Lethrense and Gesta Danorum
Horwendill is the name of a Jutish chieftain in Chronicon Lethrense and in Saxo Grammaticus' Gesta Danorum (book 3). Saxo Grammaticus states that Horvendill and Feng were the sons of Jutland's ruler Gervendill, and succeeded him as the rulers of Jutland. On his return from a Viking expedition in which he had slain Koll, king of Norway, Horvendill married Gerutha, the Danish king Rørik Slyngebond's daughter, who bore him a son Amleth (cf. Hamlet). But Feng, out of jealousy, murdered Horvendill, and persuaded Gerutha to become his wife, on the plea that he had committed the crime for no other reason than to avenge her of a husband by whom she had been hated. The Chronicon Lethrense (and the included Annales Lundenses) tell that the Danish king Rorik Slengeborre installed Horwendill and Feng as rulers in Jutland, and gave his daughter to Horwendill as a reward for his good services. In this version, too, a jealous Feng kills Horwendill and takes his wife.
- Thor went home to Thrúdvangar, and the hone remained sticking in his head. Then came the wise woman who was called Gróa, wife of Aurvandill the Valiant: she sang her spells over Thor until the hone was loosened. But when Thor knew that, and thought that there was hope that the hone might be removed, he desired to reward Gróa for her leech-craft and make her glad, and told her these things: that he had waded from the north over Icy Stream and had borne Aurvandill in a basket on his back from the north out of Jötunheim. And he added for a token, that one of Aurvandill's toes had stuck out of the basket, and became frozen; wherefore Thor broke it off and cast it up into the heavens, and made thereof the star called Aurvandill's Toe. Thor said that it would not be long ere Aurvandill came home: but Gróa was so rejoiced that she forgot her incantations, and the hone was not loosened, and stands yet in Thor's head. Therefore it is forbidden to cast a hone across the floor, for then the hone is stirred in Thor's head.
Guesses as to the identity of this star have included the polestar, the planet Venus, Sirius and the star Rigel which forms the toe of the constellation Orion, though if Aurvandil is to be identified with the constellation Orion one would expect to find Aurvandil himself being translated into the sky, not just his toe.
In the Old English poem Crist I are the lines (104–111):
- éala éarendel engla beorhtast
- ofer middangeard monnum sended
- and sodfasta sunnan leoma,
- tohrt ofer tunglas þu tida gehvane
- of sylfum þe symle inlihtes.
- Swa þu, god of gode gearo acenned,
- sunu soþan fæder swegles in wuldre 
- Hail Day-Star! Brightest angel sent to man throughout the earth, and
- Thou steadfast splendour of the sun, bright above stars! Ever Thou dost
- illumine with Thy light the time of every season. As Thou, begotten God
- of God, Son of the True Father, without beginning
- (From the Kennedy modern English Translation) 
The name is here taken to refer to John the Baptist, addressed as the morning star heralding the coming of Christ, the "sun of righteousness". Compare the Blickling Homilies (p. 163, I. 3) which state Nu seo Cristes gebyrd at his aeriste, se niwa eorendel Sanctus Johannes; and nu se leoma thaere sothan sunnan God selfa cuman wille, that is, "And now the birth of Christ (was) at his appearing, and the new eorendel (morning-star) was John the Baptist. And now the gleam of the true Sun, God himself, shall come."
J. R. R. Tolkien was inspired by references in the Crist poem, deriving both the character Eärendil, also associated with the morning star, and his use of Middle-earth from it (see Sauron Defeated p. 236f.). The Quenya phrase, "Aiya Eärendil, elenion ancalima!", literally "Hail Eärendil, brightest of stars!", bears a strong similarity to the line "Hail Earendel, brightest of angels" in Crist I, even so far as to use the same syntax as the Old English version.
In a personal letter given in The Letters of J.R.R. Tolkien (page 385) Tolkien talks of his understanding of the word, saying that ... "it at least seems certain that it belonged to astronomical-myth, and was the name of a star or star-group. To my mind the Anglo-Saxon uses seem plainly to indicate that it was a star presaging the dawn (at any rate in English tradition): that is what we now call Venus: the morning star as it may be seen shining brilliantly in the dawn, before the actual rising of the Sun. That is at any rate how I took it on first encountering the word, in 1914."
- Rydberg, Viktor; Anderson, Rasmus B. (2004) . Undersökningar i germanisk mythologi, första delen [Teutonic Mythology]. Kessinger Publishing. ISBN 978-0-7661-8891-4.
- Christ A, B, C
- Christ A, B, C : Kennedy modern English Translation