IT is a deeply unimpressive looking object — about the size and shape of a rugby ball, made from hardened clay and incised all over with the stick-like characters of Babylonian cuneiform.

And yet despite an unpromising appearance, it is hard to think of an artefact freighted with such significance for so many different peoples. Made shortly after Cyrus of Persia captured Babylon in 539BC, the Cyrus cylinder records how the ruler allowed deported peoples to return to their homelands and ushered in an era of religious tolerance in his new, multiethnic empire.

For Jews and Christians, it is the object that — along with passages of Isaiah — records the end of Jewish exile in Babylon. In Iran, it has by turns been used as a symbol of the Shah’s power and, most recently, when the cylinder toured Tehran in 2010, was adopted as a rallying cry for Palestinian freedom by Mahmoud Ahmadinejad.

For others, it is the first declaration of human rights, and an international symbol of religious tolerance. For Neil MacGregor, director of the British Museum, to which it belongs, it is the “first press release”.

Next year, it will become clear how the Cyrus cylinder will be read in the US, when, for the first time, it is to be lent to museums across the Atlantic.

When relations between the US and Iran are at best fragile, the interpretation of this evidence of Persia’s historic tolerance is an intriguing prospect. For MacGregor the point is about the “reasserting of the importance of the historical perspective. It is a reminder that the problems in the Middle East can be understood only in the context of the long historical framework.”

According to John Curtis, keeper of special Middle East projects at the museum, “the Cyrus cylinder is important for the expatriate Iranian community in America, and it is important for the Jewish community”. In its role as early human-rights declaration, a replica of the Cyrus cylinder is displayed in the UN headquarters, he pointed out.

But the importance of Cyrus as a figure in the US, he said, goes right back to the founding fathers. Thomas Jefferson, for example, owned two copies of the Cyropaedia, the Greek author Xenophon’s text on the ideal education of a ruler. MacGregor added: “What appealed to the founding fathers about Cyrus was the notion of a secular state that was not on the French model. In other words, a model of a state that was equidistant from all religions, rather than either adopting a state religion, or else being anticlerical. The relic asks the question: can a state be equidistant from all religion?”

The cylinder is also, said MacGregor, a “reminder of the intricacy of Middle-Eastern politics”. The object is far from straightforward: it is not itself Persian, but Babylonian: it was found in a dig in the city, in modern Iraq, in 1879 by British Museum archaeologists, who legally acquired it from the Ottomans. There are no Persian inscriptions relating to the event at all; this is a description of events as seen from a Babylonian perspective, and describes Cyrus as having been guided by the Babylonian deity Marduk. The biblical account, meanwhile, which has strikingly similar wording, gives the credit for guiding Cyrus to Jehovah.

“Our role is to represent this as an object in the history of culture,” said MacGregor, “but what is fascinating is the reading of the objects by others”. Curtis added: “In a way, it doesn’t matter so much what the document actually says, so much as what people think it says.”

The tour — on which the cylinder will be accompanied by other treasures from the ancient Near East — is part of the British Museum’s policy of making the collection available as widely as possible “either online or on loan”, said MacGregor. — The Guardian, London