As punishment for supporting rebels in Tyre and Canaan,
the Iranian declare war on the city-states of Athenai and Sparta. King Darius, leading this expedition, said, Adakaiy fratara maniyaiy afuvāyā yadiy vaināmiy hamiçiyam yathā yadiy naiy vaināmiy, - "When I see something rebellious, I am farther beyond fear than when I do not see something rebellious."
The expedition fails at the plain of Marathon neat the city of Apollonia. Darius is forced to make a humiliating march back to Anatolia and
vows revenge. However, he dies before he can complete his war, leaving it to his son...
These people of "Yauna" demand the "liberation" of their "compatriots" to the east. How insolent! How dare they!
Seeing the difficulty in conquest with only native Persians, the empire recruits soldiers from the provinces and beyond.
However, this presents a massive problem - in both the costs of paying salaries and purchasing nonstandard supplies, and the organizational difficulty in managing dozens of nationalities and hundreds of languages.
The empire is racked with dynastic crises.
A Zoroastrian priest named Gaumāta, impersonating a prince named Bardiya, leads a rebellion to crown himself king. There is much confusion, and various Greek and Iranian sources give contradictory accounts. The official imperial inscription states: Gautāma magu adurujiya avathā athaha adam Bariya amiy. Adam khshayathiya. ("Gautama the Magician lied and said I am Bariya. I am king.") When the rebellion is over, the king sets up a new system of government: a pure monarchy supervised by the government's official Jewish priests. However, other religions are still tolerated.
King Cambyses, long viewing the Egyptians as a threat, invades over the Sinai peninsula. His army takes over the north of the country. However, his gains are short-lived. The Egyptian remnants retake their cities, to the gratitude of a relieved populace, and kick out the invaders. The land of Kemet remains its own.
Persian imperial soldiers explore the remains of an ancient city, believed now to be either a Hittite settlement or a failed Greek colony. Meanwhile, Persian-speaking settlers begin to colonize
the traditionally Greek area of Anatolia. They incorporate the city of Gordion, originally a small Greek farming town, into the empire, as an important outpost for trade and military.
By this time, scientists and astronomers in the city of Babylon have compiled one of the largest collections of mathematical writing of all time. They begin to put this knowledge to use in creating a standard, empire-wide calendar for religious observances, trade and agriculture.
To the north, a new people is sighted. The Celts. Little is known about them outside of the Greek stories.
The caravan trade through the precarious mountains and deserts of Central Asia has lasted for hundreds of years. However, this is the first time Iranians come into direct contact with the Chinese.
Eastern merchants seeking precious metals meet western merchants seeking silk. Direct trade is not established yet, and India acts as a middleman for some time.
With planned invasions not coming to fruition, and various distractions to the east and south, the Persian king signs a peace treaty with the Greeks. Rather than give up the Mediterranean cities, he sends emissaries with precious knowledge of agriculture -
something severely lacking in the harsh, mountainous terrain of Greece. The promise of Iran's trade now has more influence on Greece than does the threat of its armies.
After hundreds of years, the rebellious city of Artaxata is captured. There is surprisingly little resistance. Steeled by the experience of this war, a great general returns to Babylon. His valor and genius inspires all units he leads, and the reforms he introduce ensure their continued success. (Though with not as much permanence as settling in the city would

)
With both a calendar and a unified code of laws,
the Persian government moves to begin minting a standard currency. It replaces the various Greek and Babylonian coins previously used around the empire, and becomes one of the most widely-used and influential currencies in the Mediterranean world. Not bad for former nomads.
Border fortifications dating back to the beginning of the empire are updated and unified. Bureaucrats from the capital of iraji take over responsibility for the protection of the frontier against nomads, such as the
Scythians (Sākā
and the Xiongnu. The effectiveness of this system prevents barbarians from ever again breaching the borders of the empire.
Wanting to learn more about their strange and foreign neighbors, the city of Gordion raises money for a scouting expedition to the Celtic border. The scouts are deputized as official emissaries of the Persian King, and
cross the Bosporus on an ingeniously-engineered bridge of boats.
The Persians meet Brennus, the warlike leader of the foreigners. He is a very strange man - and his red hair is rumored to be the mark of soullessness. The Iranians share their knowledge in exchange for Celtic metalworking equipment, and then immediately rush to leave this "land of devil gingers." They are disappointed when a messenger comes from the King, ordering them even further west.
A second Iranian army enters Egypt, this time much larger and with the intent of permanently ending the tyranny of the Egyptian "god-kings". In the same year, a Iranian priest marries the daughter of a prominent Greek merchant. In their "big fat Greek wedding," religious leaders from both nations gain closer ties. "Never again will the Jewish peoples fight each other!" exclaims one. How little does he know...