Artefact 90920 is wending its way from the British Museum to Tehran, where it has fired debate between those who see it as a national icon and others who say it represents all that is worst about Iran's pre-Islamic past.
The controversial relic is an unassuming 23-centimetre-long (9-inch) cylinder of baked clay covered in densely packed lines of Babylonian cuneiform script.
It is generally agreed to be the world's first human rights charter - but Islamic conservatives say it is redolent of paganism and a monarchy ousted in the 1979 revolution.
The British Museum's keeper of Near Eastern antiquities John Curtis said the museum planned to loan the cylinder after it was shown in Paris and Berlin but a date was not yet set. Iranian archaeologists hoped it would arrive in 2006.
When empire-building Persian monarch Cyrus the Great overwhelmed Babylon's army east of the river Tigris in 539 BC there was no victorious pillaging or torching of homes.
Instead he wrote his charter, the Cyrus cylinder, declaring that each man would be free to worship his own gods, no race would oppress another and no man would be enslaved.
In a move with sharp modern resonance, the conqueror also gave right of return to refugees.
Shahrokh Razmjou, a scholar at the National Museum of Iran working on a fresh translation of the cylinder, said the artefact kindled intense emotions among many Iranians.
"People feel strongly about it because it is about freedom and giving freedoms," he said. "People want to keep the connection to that golden period."
He said a joyous gasp had rippled around a crowded Tehran lecture theatre when British Museum Director Neil MacGregor announced to them that the cylinder would be loaned to Iran.
Although many Iranians still name their children after ancient royalty and deities - Cyrus, Darius, Xerxes, Roxana and Anahita - others are less comfortable with pre-Islamic times.
An editorial in the hard-line Jomhuri-ye Eslami daily insisted the spiritual father of the modern nation, Ayatollah Ruhollah Khomeini, would not have approved of the loan.