The great cities of the Persian (Achaemenid) Empire were its royal capitals: Pasargadae and Persepolis in the Persian homeland of Fars, Susa in the lowlands of Khuzestan, Ecbatana (modern Hamadan) in the Zagros, and conquered Babylon in Mesopotamia. Around them sat a ring of provincial seats such as Sardis in Anatolia, Memphis in Egypt, Bactra in today’s Afghanistan and Taxila near the Indus. Founded by Cyrus the Great in 550 BC and conquered by Alexander the Great in 330 BC, the empire covered roughly 5.5 million km² at its height under Darius I (522–486 BC). It stretched from the Balkans and Cyrenaica in Libya to the Indus Valley, which made it the largest empire of its time. Its kings held it together with governors called satraps, two official languages (Persian and Aramaic) and a network of post roads. The Royal Road from Susa to Sardis was the most important of them.
The tour below runs roughly west to east, city by city: what happened in each, when, and what you can still see on the ground.
Sardis, the western terminus of the Royal Road
Sardis, near the village of Sart in Turkey’s Manisa Province, was the capital of Lydia before it was a Persian city. Its last king, Croesus, struck first after Cyrus conquered Media in 550 BC, attacking Pteria, a Persian vassal. Cyrus beat the Lydian army on the plain north of the city in December 547 BC and took Sardis after a 14-day siege, capturing Croesus with it. Under Persian rule the city became the seat of the satrapy the Persians called Sparda, and the western end of the Royal Road. It was Persia’s window on the Greek world. The Aramaic alphabet came into use beside Lydian, and governors such as Tissaphernes and Cyrus the Younger laid out orchards and hunting parks, the Persian paradeisoi.
Sardis was also where Persian rule in the west first broke down. In 498 BC, early in the Ionian Revolt, Ionian Greeks backed by troops from Athens and Eretria captured and burned the lower city. Persia’s invasions of Greece followed: the campaign defeated at Marathon in 490 BC, and Xerxes’ expedition of 480–479 BC, during which his army captured Athens and burned the Acropolis. Sardis joined UNESCO’s World Heritage List in 2025.
The road took neither the shortest nor the easiest line, so archaeologists think its western sections may first have been built by Assyrian kings; Darius I improved the existing network into one post road. Its 2,699 km had 111 posting stations kept stocked with fresh horses. A relay of royal couriers could carry a message the whole way in about nine days; on foot the journey took ninety. In 1961 S. F. Starr traced the stretch between Gordium and Sardis by finding the abutments of its old river bridges.
Pelusium, Memphis and Darius’s canal to the Red Sea
Egypt was the empire’s great prize in Africa. Cyrus’s son Cambyses II invaded in 525 BC and beat the pharaoh’s army at Pelusium, on the eastern edge of the Nile Delta about 30 km south-east of modern Port Said. Sieges of Gaza before the battle and of Memphis after it completed the conquest. Cambyses became the first king of Egypt’s Twenty-seventh Dynasty, and Memphis, the old capital at the head of the delta, became the seat of the Persian satrap. Herodotus, who visited while the Persians still ruled, noted that they kept up the dikes that protected Memphis from the Nile floods.
Darius I then joined Egypt to the Persian heartland by water. He had a canal dug through the Wadi Tumilat from the easternmost (Bubastite) branch of the Nile to Lake Timsah, which led on through natural waterways to the Red Sea. It was a forerunner of the Suez Canal. He marked the opening with stelae in Old Persian, Elamite, Babylonian and Egyptian. The best preserved, the Chalouf stele of pink granite, was found in 1866 by Charles de Lesseps, son of the Suez Canal’s builder, about 30 km from Suez. In its Old Persian text Darius says that once the canal was dug, ships went from Egypt through it to Persia. For the river and delta this canal drew on, see our guide to the geography of ancient Egypt.
Babylon and Susa, the lowland capitals
Babylon fell to Cyrus in 539 BC, ending the last native dynasty of Mesopotamia. A clay cylinder buried as a foundation deposit after the conquest presents Cyrus as the choice of Babylon’s god Marduk, welcomed into the city in peace. Found in the ruins in 1879, the Cyrus Cylinder is now in the British Museum. Babylon stayed one of the empire’s four capitals, with Pasargadae, Susa and Ecbatana. It also rebelled: native kings briefly held the city in 522, 521 and 482 BC before Persian armies took it back. It remained Persian until Alexander arrived in 331 BC. Our guide to Mesopotamia traces the 3,000 years of city-building before Cyrus.
Susa, now the town of Shush in south-western Iran, lies between the Karkheh and Dez rivers about 250 km east of the Tigris. It had been the capital of Elam, and Cyrus took it around 540–539 BC. Under Cambyses it became one of the four Achaemenid capitals, and it served as the winter residence of the court. Darius chose the plan for a new palace there in 515 BC. Its Apadana, an audience hall of stone columns and clay walls with a brick facade, was completed under Xerxes. Glazed reliefs of the royal guard, winged lions and lotus flowers covered its inner walls. Part of it burned in Artaxerxes I’s reign and Artaxerxes II rebuilt it. Susa was the eastern head of the Royal Road, and loot from older wars still lay there: the stele of Hammurabi’s law code was dug up at Susa in 1901. UNESCO listed the site in 2015.
Behistun and Ecbatana on the Zagros road
The road from Babylon up onto the Iranian plateau climbs the Zagros through what is now Kermanshah Province. There, on a cliff at Mount Behistun, Darius I had his own account of how he came to power carved in Old Persian, Elamite and Babylonian. It records that after Cambyses died he fought nineteen battles in a single year, ending in December 521 BC, against rebels and pretenders across the empire. The relief above shows Darius with his foot on the defeated pretender Gaumata and nine captives, hands tied and roped at the neck, standing before him to represent conquered peoples. Henry Rawlinson began copying the hard-to-reach inscription in 1835 and took until 1847 to send a full copy of the Old Persian text to Europe. As the longest known trilingual cuneiform inscription, it proved central to deciphering cuneiform. UNESCO listed Bisotun in 2006.
Further up the same road lies Ecbatana, under the modern city of Hamadan at the foot of Mount Alvand. Herodotus says the Median king Deioces made it his capital in 678 BC and ringed it with seven walls. That makes it the first capital in Iranian history. Cyrus took it when he overthrew the Median king Astyages in 550 BC, and the Achaemenids kept it as their cool summer capital on the road between Persepolis and the west. After his defeat at Gaugamela, Darius III fled there to raise a new army. Learning in 330 BC that Alexander was coming, he left Ecbatana for Bactria through the Caspian Gates.
Pasargadae and Persepolis in the Persian homeland
The empire’s homeland was Persis, the modern province of Fars, high in the southern Zagros. Cyrus built his capital at Pasargadae, about 90 km north-east of Shiraz, near the place where he defeated Astyages. The site covers 1.6 km² and holds two palaces, the hilltop fortress of Toll-e Takht, and the oldest known example of the Persian chahar bagh, the four-part garden. Its best-known monument is the tomb generally identified as Cyrus’s own: a gabled stone chamber 3.17 m long, 2.11 m wide and 2.11 m high on six broad steps. Arrian, drawing on Aristobulus, a companion of Alexander, describes the king visiting the tomb and being grieved to find it plundered. In 2006 archaeologists also identified the remains of Cambyses II’s tomb near Toll-e Takht.
Darius moved the dynastic centre to Persepolis, on the Marvdasht plain ringed by the southern Zagros, where the earliest remains date from 515 BC. It was the empire’s ceremonial capital, a palace complex and citadel on a great stone terrace. Until recently most archaeologists held that it served chiefly for Nowruz, the Persian New Year, when the nobility and subject lands brought gifts to the king, as its stairway reliefs show. Visitors entered through the Gate of All Nations, built under Xerxes I (486–465 BC). Inside, the Apadana’s roof rested on 72 stone columns; 13 still stood at the start of the 20th century, and a fallen one was put back up in the 1970s. Thirteen kilometres north-west, at Naqsh-e Rostam, four royal tombs are cut high into the cliff, including those of Darius I and Xerxes. Alexander’s army took Persepolis in 330 BC, and the palaces burned soon afterwards. The ruins have been a World Heritage Site since 1979, as our guide to Persepolis explains.
Bactra, Cyropolis and Taxila on the eastern frontier
East of the plateau the empire reached into Central and South Asia. Bactra, today Balkh in northern Afghanistan about 24 km north-west of Mazar-i-Sharif, was the capital of the satrapy of Bactria and gave the region its name. Its satrap had a hand in the empire’s final act. In 330 BC Bessus, satrap of Bactria, joined a coup against the fleeing Darius III; as Alexander’s cavalry closed in, he and two fellow conspirators wounded the king with javelins and left him to die. Bessus then proclaimed himself King of Kings and tried to hold the east until 329 BC.
Beyond Bactria, Cyrus founded Cyropolis, “the city of Cyrus”, to mark the north-eastern border of his empire. Its exact site is still undetermined. Khujand in Tajikistan and Kurkath near the river are among the candidates, and Alexander may have refounded it as Alexandria Eschate. To the south-east, Cyrus began annexing land west of the Indus around 535 BC. Around 518 BC Darius pushed on as far as the Jhelum in today’s Punjab, organising the conquests as Gandara, Hindush and Sattagydia. Taxila, near Rawalpindi in Pakistan, has been suggested as the seat of Hindush from about 500 to 330 BC. Its king submitted to Alexander in 326 BC.
The eastern roads of the empire did not end at the frontier. Stretches across the plateau, such as the Great Khorasan Road, later carried caravans between China and the Mediterranean, a story told in our guide to the geography of the Silk Road.