Histiaeus (d.c.494/493) was the Tyrant of Miletus during the reign of Darius I and was said to have helped save the Persian army during an expedition across the Danube, before later turning on Darius and encouraging the Ionian Revolt of 500/499 BC.
Histiaeus was the ruler of the Greek city of Miletus on Anatolia at a time when the area was ruled by the Persian Empire. In 513 Darius I, the Persian Emperor, decided to campaign against the Scythians north of the Danube. The Persians left their Greek subjects in charge of the bridge over the Danube while they attempted to come to grips with the nomads. Darius's campaign soon became bogged down, and he decided to return to the bridge. While he had been away the Greeks had been discussing if they should destroy the bridge. Histiaeus managed to convince them to leave the bridge intact, allowing Darius and his army to retreat intact. Histiaeus was rewarded with lands in Thrace as a reward.
Histiaeus soon fell out of favour with Darius, and was forced to move to Susa, where he became a virtual prisoner. His son in law Aristagoras replaced him at Miletus.
According to Herodotus Histiaeus began to send messages to Aristagoras in an attempt to convince the Ionian cities to revolt. In order to get the message past Darius he had one of his slaves shave his head, tattoed the message on his head, and then allowed his hair to re-grow. Once the message was hidden, the slave was sent to Miletus, where he told Aristagoras to shave his head and read the message. One can't help think a verbal message would have been easier.
When the revolt finally broke out, Histiaeus convinced Darius that he could put down the revolts and then go on to conquer Sardinia for him (a rather random promise). Darius was convinced, and allowed Histiaeus to return to Asia Minor. He arrived at Sardis at about the same time as the failure of the first Persian counterattack in 397-396, and just after Aristagoras, his successor at Miletus, had lost his nerve and fled to Thrace.
He was unable to convince the local Persian satrap, Artaphernes, of his loyalty and was soon forced to flee to Chios. The Chians didn’t trust him either, and locked him up. He was soon able to convince them that he was on their side, and was released. His is said to have told the Chians that Darius had planned to swap the populations of Ionia and Phoenicia, a rather odd plot.
Next he attempted to ferment trouble at Sardis, using a messenger called Hermippus of Atarneus to take messages to discontented Persians in the city. Hermippus betrayed him and took the messages straight to Artaphernes, who used them to gather evidence against the potential rebels, who were then executed.
Histiaeus's next move was an attempt to regain power at Miletus. He was rejected by the Milesians, and an attempt to regain power by force failed. He was wounded in the attempt and had to return to Chios. By now the Chians appear to have been sick of him, and refused his request to be given a fleet.
His next move was to Mytilene on Lesbos. The Lesbians granted him eight ships, and he took them to Byzantium, where he became something of a pirate, intercepting ships coming from the Black Sea and only releasing them if they acknowledged him as the Ionian leader.
In 494 the Persians launched a major offensive against Miletus. The Ionians gathered a major fleet, but they were defeated in a naval battle at Lade (494 BC), an island close to Miletus. Miletus was besieged and captured, and the Ionian cause was close to collapse.
Histiaeus's motives after this battle are hard to understand. If he was attempting to act as the leader of Ionian resistance then his first actions are difficult to excuse. He left Byzantium, and sailed to Chios. A local garrison refused to let him pass, he attacked them, and then conquered the island with the help of his Lesbian allies. The Chians had suffered the heaviest losses at Lade, where they had refused to flee until most of their fleet had been sunk.
He used Chios as a base for an attack on Thasos, off the coast of Thrace. This attack had to be abandoned after the Persian fleet left Miletus and began to advance around the coast of Asia Minor. He withdrew from Chios and moved to Lesbos, where he prepared to defend the island.
Supplies soon ran short, and Histiaeus decided to raid the mainland to harvest food in Atarneus, on the mainland opposite Lesbos. He landed at Malene, close to the city, but unfortunately for him a Persian army under a general called Harpagus was in the vicinity. The Persians intercepted Histiaeus, and defeated him in battle (battle of Malene, 494 BC).
Histiaeus was taken to Artaphernes, who decided that it was too dangerous to send him to the court of Darius, where he would probably be able to talk his way out of trouble. Instead he had Histiaeus impaled and sent his embalmed head to Darius. Artaphernes was right to be concerned. Darius castigated him for executing Histiaeus, and ordered his head to be treated with respect and buried with honours.