According to Herodotus, Deioces founded Ecbatana around 678 BCE as the capital of the newly unified Medes. He designed it as a statement of power: seven nested fortifications, each in the color of a celestial body, with the outer circuit matching the size of Athens itself. The royal palace within the innermost wall had hundreds of rooms. People built their houses outside the fortress, clustered around the base of the hill. Some archaeologists attribute the construction to Phraortes, the second Median king. Older legends credit the legendary queen Semiramis or the mythical king Jamshid. What is certain is that the city existed, that it served as the seat of Median power, and that the Assyrians, despite two centuries of campaigns in the central Zagros, never seem to have reached it. Stone reliefs from the Neo-Assyrian Empire depict Median citadels ringed by concentric walls, lending credibility to the Greek descriptions.

When Cyrus the Great defeated the last Median king Astyages in 550 BCE, Ecbatana changed hands but not function. The Achaemenids kept it as a summer capital and treasury, positioned on the royal road connecting Persepolis to Sardis. The Nabonidus Chronicle records the moment of transfer with bureaucratic precision: Cyrus marched against Ecbatana, seized the royal residence, took its silver, gold, and valuables as booty. The city was renowned for its wealth and splendid architecture. When Darius III faced Alexander the Great in 330 BCE, the king ordered hundreds of hiding places built within the city to conceal treasures. It was not enough. Alexander captured Ecbatana, looted its gold and silver decorations, and ordered the assassination of his own general Parmenion on its grounds.

Under the Parthians, Ecbatana became the empire's main mint, producing drachms, tetradrachms, and bronze denominations. The area had a reputation for horses and wheat. Graphite, gold, platinum, antimony, and iron were found in the surrounding mountains. The Battle of Ecbatana in 129 BCE marked the Seleucids' last attempt to reclaim their eastern territories, when Antiochus VII Sidetes fell to the Parthian king Phraates II. After that defeat, Seleucid power retreated permanently to Syria. Ecbatana endured through the Sasanian period until the Muslim conquest after the Battle of Nahavand in 642 CE. The city survived that transition, but not what followed: around 1220, the Mongol invasion destroyed it completely. In 1386, Timur sacked what remained, and the population was slaughtered.

The great challenge of Ecbatana's archaeology is that Hamadan, a city of over 500,000 people, sits directly on top of it. Charles Fossey conducted the first excavation in 1913, spending six weeks on the Mosalla hill and three months on the eastern section. He found fragments of column bases with arabesques, glazed bricks, faience tiles, and the sculptured head of a prince. The 30-meter-high Tell Hagmatana is almost certainly the site of the Median citadel and Achaemenid royal buildings. In 1969, the Iranian government began buying property on the tell to clear space for archaeology, but excavation did not start until 1983. By 2007, twelve seasons of digging had occurred. Excavations in 2006 reached only Parthian layers, but this says nothing definitive: the 35-hectare site has barely been scratched.

Ecbatana appears in sources far beyond the Greek historians. The Bible mentions its citadel in the Book of Ezra, noting it as part of the national archives during the reign of Darius I. Ancient authors called it Caput Mediae, the capital of Media, and the Royal Seat. The poet Archibald MacLeish placed it in his catalogue of fallen empires in the poem You, Andrew Marvell, using the archaic spelling Ecbatan. Historians now consider the identification of Ecbatana with Hamadan secure, ending a long debate about alternative locations. The city endures in the way that ancient capitals often do: not as ruins set apart in a desert, but as a living city built on the bones of its predecessors, where construction crews occasionally turn up artifacts from a time when this gentle hill held the palace of the Medes and seven walls painted in the colors of the heavens.