The three that circulate
You will read that the island is named for a hero called Milos, sent here by Aphrodite. You will read that he was instead a son of the river god Skamandros. And you will read that the name is not a person at all, but milos, a millstone — a reference to the obsidian and the pumice that this island has been exporting since the Stone Age.
The millstone one sounds the most sensible, which is usually a warning. All three come from travel pages and commercial copy, and no ancient citation has been found for any of them. Not a weak one. None.
The one that looked like a source
There is a figure named Melus who appears to give the whole thing a footing. He comes from Servius, a late commentator on Virgil, in a note on the Eclogues.
Go and look at the passage and it is about Delos, and a city called Melon.
It is not about this island. The connection between that note and this place appears to be modern — somebody noticing that one name resembles another and joining them up. Which is not a forgery and not even really an error. It is just the ordinary way a plausible sentence gets into circulation and then gets repeated by everyone who needs one.
So the position is not that the island's naming myth has been lost. It is that there does not appear to have been one. The name is older than every explanation anybody has offered for it, and all of the explanations are recent.
The most famous thing that happened here
Milos has one ancient text of the first rank, and it is not a myth at all.
In 416 BC an Athenian fleet arrived to demand the island's submission. Thucydides sets the scene at the opening of what has come down to us as the Melian Dialogue:
The Melians are a colony of Lacedaemon that would not submit to the Athenians like the other islanders, and at first remained neutral and took no part in the struggle, but afterwards upon the Athenians using violence and plundering their territory, assumed an attitude of open hostility.
Crawley's translation, first published in 1874. What follows is the most quoted argument about power in ancient literature — the Athenians explaining, with great patience, that questions of justice arise only between equals, and the Melians answering that they would rather not accept that. The island did not submit. It went badly.
And here is the thing that ought to be said out loud on an island this small: there is nowhere to stand. No identified siege works, no marked site, no sign, no installation. The most consequential hours in the island's recorded history have left, so far as anyone has established, nothing you can look at.
Which is the essay
An island whose name nobody can account for, and whose most famous hour has no address.
Both of those are absences, and it is tempting to treat an absence as a failure of research. It is not, here. The ground on Milos is exceptionally legible — this is a place that has been read, and quarried, and argued over, and it will tell you a great deal about itself if you look at what it is made of.
It just will not tell you what it is called, or where it was defeated.