Lycurgus was the name the Spartans gave for their mythical founder figure, a Spartan who had supposedly lived in the late 9th century and had set up the Spartan society as we see it in the classical period. Almost all of our details for his life come from a biography by Plutarch, written c. 100 A.D. (date to be significant in a moment). The story the Spartans told went thusly:

Once upon a time … there was a Spartan named Lycurgus, and he was the very best Spartan …

Lycurgus had been the younger brother of one of Sparta’s two kings, but had left Sparta to travel when his brother died, so that he would be no threat to his young nephew.

After a time, the Spartans begged Lycurgus to come back and reorganize society, and Lycurgus – with the blessing of the Oracle at Delphi – radically remade Spartan society into the form it would have for the next 400 years. He did not merely change the government, but legislated every facet of life, from child-rearing to marriage, to the structure of households, the economic structure, everything. Once he had accomplished that, Lycurgus went back to Delphi, but before he left he made all the Spartans promise not to change his laws until he returned. Once the Oracle told him his laws were good, he committed suicide, so that he would never return to Sparta, thus preventing his laws from ever being overturned. So the Spartans never changed Lycurgus’ laws, which had been declared perfect by Apollo himself. Subsequently, the Spartans accorded Lycurgus divine honors, and within Sparta he was worshiped as a god.

And that’s how Lycurgus remade Sparta. The End.

The role Lycurgus serves in the sources is as the perfect, infallible founder figure. No less than the Oracle at Delphi – the divine word of Apollo – declared Lycurgus a god (Hdt. 1.65.3). For later sources who, we must stress – believe their own religion (as people everywhere are wont to do) – that means, essentially a priori that Lycurgus’ “constitution” must be practically flawless and all flaws must stem from its imperfect implementation.

But – wait a second – what is our evidence for the actual person of Lycurgus or the character of the state he set up?

Remember how I said Lycurgus is dated to the late 9th century – specifically the 820s B.C. or so. That’s a huge problem. The earliest Greek literature comes from around (very roughly – there is deep scholarly debate here that I’m glossing over) the mid-8th century (c. 750 or so) and is entirely mythological in nature. The first actual history is Herodotus, writing in the mid-400s. The earliest historical event we have evidence for is the Lelantine War (c. 700ish), at least a century after the life of Lycurgus. None of our sources have anything to go on about Lycurgus – save for what the Spartans – who already worship this figure as a god – tell them. Crucially, Tyrtaeus, writing in the 650s B.C., while he does mention the rhetra (an oracle the Spartans received concerning the arrangement of their government) does not mention Lycurgus (although Plutarch is quick to connect the two, Plut. Lyc. 6.5), meaning that the earliest source for Lycurgus’ existence is Herodotus.

Wait, it gets even better – the one thing we do know about Lycurgus’ laws is that they were not written down (Plut. Lyc. 13.1). Also, Lycurgus supposedly took steps to prevent his remains from returning to Sparta (Plut. Lyc. 29.5-6, but cf. 31.4) and no continued family line, which seems like exactly the sort of explanation you put at the end of a good campfire story for why there was absolutely no trace of such an important man save his legend. So not only the details of Lycrugus’ life, but also the society he created will have lived as oral tradition – potentially changing from one telling to the next, being embellished or expanded – for generations before being committed to the permanent, unchanging memory of written history.

In short, our only evidence for Lycurgus are the campfire stories told about him by people who worshiped him as a god, as related to individuals centuries later. Which is to say that, by historical standards, there is no reliable evidence at all that Lycurgus existed.

[…]

Lycurgus is often set against Solon – the early 6th century Athenian reformer. It is true that Athenians also tend to attribute things to Solon that were later developments, but we need to note the key differences: Solon comes two centuries after Lycurgus (thus, unlike Lycurgus, in the historical period), didn’t receive divine honors and most importantly writes to us (he wrote poetry, some of which survives), so that we can know he was an actual real person. Asking students – as I have seen done – to compare a real, flawed reformer with an idealized, semi-mythical demi-god without any kind of guidance as to the nature of these two figures is, quite frankly, educational malpractice.

Bret Devereaux, “Collections: This. Isn’t. Sparta. Part III: Spartan Women”, A Collection of Unmitigated Pedantry, 2019-08-29.