There are only a few ancient texts about the Mede Datis, who must have been one of the most important generals in the Achaemenid empire in the first quarter of the fifth century BCE. The most important information can be found in the Histories by the Greek researcher Herodotus of Halicarnassus (c.480-c.429).
In 499 BCE, the Greeks in Asia Minor, better known as the Ionian Greeks or Ionians, revolted against their Achaemenid overlords. The pro-Persian leaders were taken captive, Persian garrisons were forced to surrender and in the summer of 498, Sardes, the capital of the satrapy of Lydia, was destroyed. The Persian king Darius I the Great sent armies to suppress the revolt; the last Ionian stronghold, Miletus, had to surrender in November 494.
Herodotus describes the events in the fifth and sixth books of the Histories. He does not mention Datis, but from an inscription, we know that he was present: in 495, he conquered Rhodes, the island that guarded the entrance of the Aegean Sea. Unfortunately, this inscription is comparatively young and it may be that the presence of Datis is an invention by a Rhodian patriot who wanted to prove that his ancestors had been loyal to the Greek rebellion - something that Herodotus does not tell.
If the Rhodian inscription is a forgery, it is a very good one, because we know from the Persepolis fortification tablets that Datis was indeed involved in the suppression of the Ionian revolt. In February 494, he received special rations to make a tour of duty:
Seven rations of wine to Datiya. He carries a document, sealed by the king. He came from Sardes by the pirradaziš and went to the king at Persepolis. Month eleven, year twenty-seven. Written by Hidali.note[PFTs Q 1809. The pirradaziš was the system of horse changing on the Royal Road between Sardes and the capitals of the Achaemenid empire.]
This document proves that Damis has indeed been in the west, which makes it likely that he commanded a naval action against Rhodes in 495, and makes it possible that Datis was the commander of the Persian armada during the naval battle off Lade on 20 October 494, which marked the beginning of the siege of Miletus.
In the summer of 490 BCE, king Darius sent a new expedition to the west. Six hundred ships were assembled in Cilicia and set out to bring troops across the Aegean Sea. The commanders of this expedition were Datis and Artaphernes. Herodotus presents the expedition as a punitive action against Eretria and Athens, who had taken part in the Ionian Revolt. But he is almost certainly wrong, because the army was too small to attack Athens. In reality, the aims of the expedition of Datis and Artaphernes were to add the Aegean islands to the empire, and, in doing so, create a buffer zone between Ionia and the Greek mainland. The same project had been proposed by the Greek politician Aristagoras of Miletus to Artaphernes' father Artaphernes the Elder, who had in vain attacked Naxos (c.499 BCE). The Persian aims were, therefore, to conquer Naxos and the other islands, and to occupy Euboea (with its capital Eretria). They also tried to bring back the former ruler of Athens, Hippias, to his home town.
They were successful. First, they added Naxos to the Achaemenid empire, the largest island in the Aegean sea, situated in its center. The Greek cult center Delos was seized immediately afterwards. The god Apollo, the alter ego of the Persian "wise lord" Ahuramazda, received a grand sacrifice. A few days later, on 3 August, Datis and Artaphernes took Eretria. (Its inhabitants were deported to Elam.)
On 7 August, they landed at Marathon, some twenty-five kilometers from Athens. Although an Athenian army came to block the road to the south, it did not dare to attack the Persians, who were able to pillage the country for five days. Since the Athenians refused to offer battle, Datis and Artaphernes decided to leave early in the morning of 12 August. When they were boarding, the Athenians unexpectedly attacked and inflicted heavy losses on the Persian troops.
Herodotus' account of the battle of Marathon is our most important source. (A summary and a comment can be found over here.) He wants us to believe that Marathon was an important victory, but this is exaggerated. It was a rearguard action, and we know for certain that Artaphernes remained in the king's favor. It is likely that Datis had the same experience. After all, from now on, the Aegean Sea was under Persian control, preventing new Greek attacks on Persian dominions.
Not all Greeks were convinced by Herodotus' story. There is one Greek text, written c.100 CE, which gives us the Persian side of the story - Marathon had been a minor setback.note[Dio Chrysostom, Oration 11.148-149.] Unfortunately, we do not know whether the author gives us reliable information from an ancient Persian source, or invents this story.
The Greek historian Ctesias of Cnidus, who is not know for his reliability, states that Datis died during the battle of Marathon. The Athenians refused to return his body when the Persians asked for it. There is no way to verify or refute this statement.note[Ctesias, Persica §22.]
Datis had two sons, Harmamithres and Tithaeus, who commanded the cavalry during the Greek expedition of king Xerxes in 480 BCE.
- N.G.L. Hammond, 'The expedition of Datis and Artaphernes', in: the Cambridge Ancient History, 2nd ed, vol.4, pages 491-517