Eucleides of Athens

Most alphabets change gradually, letter by letter and generation by generation, with no single moment anyone could point to and call the change. The Greek alphabet used today is the documented exception, and the exception has a name and a year attached to it: Eucleides, archon of Athens in 403/402 BCE, the year the Athenian assembly formally decreed that the city would adopt the Ionic alphabet of Miletus in place of its own long-used local, or epichoric, script.

Archaic Athens had written Greek with a script that used a single letter, epsilon, for both the short e sound and the long e sound the Ionic alphabet marked separately with a repurposed old consonant, eta. Athenian omicron likewise did the work Ionic split between omicron for short o and a newly invented letter, omega, meaning great o, for long o. The Ionic system, already standard in the eastern Aegean cities that traded constantly with Athens, offered a more precise and increasingly familiar alternative, and the decision under Eucleides's archonship made it official rather than merely convenient.

The date is unusually well anchored because 403/402 BCE was already a marked year in Athenian political history, the year democracy was restored after the rule of the Thirty Tyrants, and sources recording that constitutional restoration record the alphabet decree alongside it. The reform did not invent new letters from nothing; eta and omega both existed already in Ionic use. What Eucleides's Athens did was choose, in one recorded act, the specific twenty-four-letter inventory that would become the Greek alphabet as every century since has known it.

Ancient Greek did not run short of the name Eucleides, and confusing the Athenian archon with either of two much better remembered men who shared it is an easy mistake to make. Euclid of Megara, active a generation after the archonship, founded the Megarian school of philosophy, studied under Socrates, and is remembered chiefly for logical paradoxes and for sheltering Plato and other Socratics in Megara after Socrates's execution made Athens unsafe for his followers; he held no civic office and had nothing to do with the alphabet. Euclid of Alexandria, active roughly a century later still, is the mathematician whose Elements systematized geometry for the ancient world and whose name survives today attached to Euclidean geometry generally; he too held no Athenian office and worked in an entirely different city, field and century.

The Athenian archon shares only the name with both of them, and the confusion is compounded by "Eucleides" and "Euclid" being simply two English renderings of the identical Greek name, so a loosely sourced reference can easily attach the archonship, the philosophy, or the mathematics to the wrong man. What can be said with confidence about the archon is narrower than what is known of either namesake: he held the office of eponymous archon at Athens for 403/402 BCE, the year restored Athenian democracy is dated from, and in that capacity presided over the decree adopting the Ionic alphabet. No philosophical school, no mathematical treatise and no other recorded act of his has come down to later readers. He is, in the fullest sense, a man known by his office and by one decision made in it.