What's the best order in which to read the Socratic dialogues of Plato? Scholars have debated this question for centuries (starting with Thrasyllus in ancient times) and it is unlikely that we'll ever come to a definitive answer. However, Catherine Zuckert (Plato's Philosophers) and Debra Nails (The People of Plato) make a compelling case for honoring not the order in which Plato wrote the dialogues but their dramatic order, focused on the central character of Socrates and ending with his death in 399 BCE (see the timeline for more details). The most thorough research on the dramatic order of the dialogues has been performed by Christopher Planeaux, whose work I lean on heavily here. (Because the Laws and Epinomis do not involve Socrates, they are not included in the following list.)
The Parmenides takes place during a Greater Panathenaea festival (held in June every fourth year), most likely the one in 450 BCE. Parmenides himself is portrayed as around 65 years old (he is thought to have been born around 515 BCE) and Socrates is portrayed as a very young man (he was born on May 3rd, 468 BCE, so in June of 450 BCE he would have just turned 18).
Alcibiades (likely born in 451 or 450 BCE) is said to have just grown a beard at the time of the Protagoras, so a date around 434 BCE is reasonable, when Socrates was around 34 years old. In his paper "The Dramatic Date of Platon's Protagoras" (work in progress), Christopher Planeaux convincingly argues for a definitive date of July 434 BCE during the Greater Panathenaea held that year.
In the First Alcibiades, Alcibiades has just finished his military training at the age of 20, and he and Socrates are about to be shipped off to the siege at Potidaea, one of the precipitating causes of the Peloponnesian War. (It appears from ancient sources that Socrates and Alcibiades shipped out in August of 432 BCE.)
The night before the Charmides, Socrates had returned to Athens from the defeat of the Athenian army after the three-year siege of Potidaea; this happened in late May of 429 BCE, near the time of Socrates's 39th birthday.
The Republic begins with a recounting of the first Athenian celebration of the festival of the Thracian goddess Bendis, which occurred in June of 429 BCE. Despite the frequent claim that this greatest of Plato's dialogues is set in 411 BCE (repeated by Catherine Zuckert), Christopher Planeaux presents a convincing case that 429 BCE makes more sense (see his paper "Socrates, Bendis, and Cephalus: Does Plato's Republic Have an Historical Setting?").
In ancient times and up to the present day, the Timaeus usually has been thought to take place the day after the Republic, followed the next day by the Critias. Although Christopher Planeaux argues for a date of 421 BCE, Nerea Terceiro Sanmartín (in her 2022 paper "The Dramatic Date of Plato's Timaeus-Critias," Greek, Roman, and Byzantine Studies 62, pp. 182–202) makes a compelling case for the traditional order: specifically, the Republic on the 19th of the ancient Athenian month of Thargelion, the Timaeus on the 20th, and the Critias on the 21st. Either 429 or 421 BCE would comport with considering the character Critias to be the grandfather of the more famous Critias of the Thirty Tyrants (who lived c. 460-403 BCE) and with the internal evidence of the dialogue Critias (in which Critias's great-grandfather Dropides heard the story of Atlantis from Solon, who lived c. 630-560 BCE).
The Minos is perhaps related to the Timaeus and Critias; for instance, D.S. Hutchinson has argued that its encomium to the mythical figure of Minos is similar to the Atlantis myth in the Timaeus. However, there is no internal evidence from within the dialogue, so a date of 429 BCE is rather speculative.
The Laches takes place after the battle of Delium in 424 BCE (where Socrates fought with distinction, as referred to in the dialogue) and before 418 BCE (the year in which Nicias died). Nails, Zuckert, and Planeaux all date it to 424 or 423 BCE, close in time to the battle of Delium; this seems reasonable, especially because in 422 BCE Socrates fought again and for the last time at the battle of Amphipolis. Socrates is around 44 years old.
Menexenus (see below) is in his early teens in the Lysis, whereas in his namesake dialogue (in ~401 BCE) he is in his early thirties; thus Christopher Planeaux argues for a date of 421 BCE. The dialogue takes place on the festival of the dead, i.e., the third day ("Chytroi") of Anthesteria in late winter or early spring. Socrates, likely having recently married Xanthippe, is nearly 49 years old.
Because the sophist Hippias was from Elis, which was allied with Sparta during the Peloponnesian War, it's plausible that he was unable to visit Athens until the Peace of Nicias from 421 to 418 BCE; therefore a date around 420 BCE seems appropriate for both the Hippias Major and Hippias Minor. Christopher Planeaux argues that Hippias himself was an envoy to Athens during negotiations for the "Quadruple Alliance" in May, June, or early July of 420 BCE — and that these dialogues could plausibly be placed then.
The Symposium takes place two nights after the playwright Agathon won a prize with his first tragedy, which happened in 416 BCE (but see below on the date of the retelling). Socrates, who is nearly 52 years old here, and Xanthippe have recently welcomed into the world their first son, Lamprocles.
Why all this talk about Hipparchus (an Athenian "tyrant" who was assassinated in 514 BCE) and the statues of Hermes that he had set up throughout Athens and the rest of Attica? It seems likely that the Hipparchus can be dated to 415 BCE, after the shocking desecration of these statues right before the Sicilian Expedition during the Peloponnesian War.
The Ion is set during or after the Sicilian Expedition of 415-413 BCE (when the Athenians were desperate for military leaders — notice the banter about rhapsodes being good generals) and before the Ionian revolt of 412 BCE (since Ion's home city of Ephesus is described as still under Athenian rule). We can further pin down the date to the spring of 414 BCE, because Socrates mentions the upcoming Greater Panathenaea to be held in June of 414 BCE. Socrates is just shy of 54.
The Euthydemus takes place very soon after the brothers Euthydemus and Dionysodorus arrived in Athens along with the other exiles from the panhellenic colony of Thurii in 412 or 411 BCE; notice how Crito thinks Euthydemus and Dionysodorus are "a new importation of Sophists" early in the dialogue. Christopher Planeaux argues for a dramatic date of 418 BCE, but I don't see how to square that with the expulsion from Thurii.
The Erastai (also known as "The Rival Lovers") is set in the school of the poet and orator Dionysius Chalcus, who helped to found Thurii in 443 BCE and likely returned to Athens along with the rest of the colonists in 412 or 411 BCE. Because he would have needed time to re-establish his school, the Erastai likely is set after the Euthydemus.
Christopher Planeaux (in the abovementioned article about the Republic) argues that the Clitophon takes place after Lysias returned to Athens from Thurii in 412 or 411 BCE. Because Clitophon has been engaged in apparently repeated discussions about the proper constitution of the city with Lysias and with Thrasymachus, the Clitophon might take place after both the Euthydemus and Erastai. An alternative date is 405 or 404 BCE, when there were active debates in Athens about democracy vs. oligarchy.
The Theages takes place after the general Thrasyllos left Athens to lead a military campaign in Ionia (mentioned in the dialogue), which happened in 409 or 408 BCE toward the end of the Peloponnesian War. (Note that the Theages character in this dialogue is different from the one in the Republic.)
One clue to the dramatic date of the Second Alcibiades is the quote at the end from The Phoenician Women by Euripides, which was first staged in 409 BCE. Therefore the dialogue must be set after the return of Alcibiades to Athens in May or June of 407 BCE and before he set out for the Battle of Notium (never to return to Athens) in 406 BCE. The First Alcibiades and Second Alcibiades therefore serve as bookends on the Athenian political career of Alcibiades himself.
Although the sophist Gorgias is known to have first visited Athens in 427 BCE, the Gorgias is set in 405 BCE, the year after Socrates served on the presiding Council of Athens in 406 BCE (as referred to in the dialogue) at the age of 63.
The Phaedrus is something of a puzzler. One could argue that it takes place after Lysias returned to Athens from Thurii in 412 or 411 BCE, but Phaedrus himself was banished from Athens in 415. Christopher Planeaux argues that Phaedrus likely returned after the general amnesty of 405/404 BCE (indeed, Phaedrus seems to have been living in Athens again by 404 BCE). Debra Nails argues for a dramatic date of 418-416 BCE and speculates that Lysias visited Athens around that time; she pins this on Socrates's question about whether Lysias was "in the town", but since his family lived in the Athenian port of Piraeus this is not definitive ("the town" was Athens proper; compare Brooklynites going into "the city"). Its setting just outside the walls of Athens might indicate that it takes place after the surrender of Athens at the end of the Peloponnesian War in April of 404 BCE; internal references to the stifling heat of the day indicate that the dialogue takes place in high summer. Polemarchus (mentioned in the dialogue) was still alive at the time but he was executed by the "Thirty" in 404 BCE, so the summer of 404 is the latest possible date for the dialogue.
The Meno is set before the death of Meno himself in 401 BCE as described by Xenophon in the Anabasis, his account of the campaign of the famous "Ten Thousand" Greek mercenaries in Persia. For various reasons detailed by J.S. Morrison long ago (see his 1942 paper "Meno of Pharsalus, Polycrates, and Ismenias," Classical Quarterly 36, pp. 57-78), the Meno can be dated to early 402 BCE, when Meno was a guest of Anytus in Athens. Significantly, at the end of the dialogue Socrates has a difficult interaction with Anytus, who became one of his accusers in 399 BCE (see the Apology.
The Menexenus is set immediately prior to a public funeral ceremony for Athenian war dead. A likely date is the late fall or early winter of 403 BCE (as Christopher Planeaux prefers) or of 401 BCE (as Debra Nails prefers). The latter date seems slightly more plausible, since the funeral oration of Aspasia recounted by Socrates mentions events from throughout the Peloponnesian War as well as from the suppression of the Athenian oligarchs at Eleusis in 401 BCE. Confusingly, the oration also mentions events from the Corinthian War of 395-387 BCE (which is why Catherine Zuckert dates it, impossibly, to 387-386 BCE, 12+ years after both Socrates and Aspasia died); these might be later interpolations or involve poetic license on Plato's part. In any case, Menexenus is old enough to serve in office, so he must be at least 30, but likely not much older because Socrates observes that Menexenus is "rather young for the post" of serving on the governing council.
At the end of the Theaetetus, Socrates mentions that the next day he must go to hear his indictment on charges of impiety and corrupting the youth and expresses hope that the next day he will meet Theodorus in the same place; these events occurred in the spring of 399 BCE).
At the beginning of the Euthyphro, Socrates meets Euthyphro on the Porch of the King Archon, just before he is to be indicted.
In the Cratylus, Socrates refers several times to the conversation of the Euthyphro as having occurred that very morning (for details, see "On Causal Priority and the Dramatic Date of Plato’s Cratylus" by Colin Smith).
At the start of the Sophist, Theodorus says that he and Theaetetus have fulfilled their promise of the day before to have a conversation with Socrates (a promise made, as noted above, at the end of the Theaetetus). The Statesman is a continuation of the same dialogue.
(Christopher Planeaux deduces that the retelling of the Symposium happens immediately before the trial of Socrates, so one could profitably read the Symposium between the Statesman and the Apology.)
In the Apology, Socrates, having already been indicted, faces trial and is condemned to death on May 21st, 399 BCE.
In another brilliant insight, Christopher Planeaux identifies the time and place of the Philebus as the cell in which Socrates was jailed after his trial (note the ironic tone when at the end Socrates asks "and will you not set me free?"); thus this dialogue occurs between the Apology and the Crito.
The events recounted in the Crito take place the night before the execution of Socrates.
The dialogues end with the execution of Socrates on June 20th, 399 BCE as recounted in the Phaedo.