Just before Zahi Hawass was due to begin his lecture at a British Museum colloquium on Ancient Egypt last week, the lights blew. The symbolism was not lost on many in the audience. For the new director of the Supreme Council of Antiquities in Egypt is a man much given to rupturing what has come to be regarded as the normal order of things. While he was in London for the conference, he dropped a diplomatic bombshell. At a private dinner with the British Museum's director, Dr Neil MacGregor, he calmly announced that Egypt would be applying for the return of the Rosetta Stone.
No wonder the lights fused. The 2,000-year-old relic is perhaps the Bloomsbury museum's most important exhibit. It draws millions of people each year, and is seen by more of the museum's 5.5 million annual visitors than any other single object.
Until recently, Dr Hawass was the director of the Pyramids at Giza, but last year he took over as secretary general of the Supreme Council of Antiquities. He has been throwing his considerable weight about ever since.
In recent weeks he has fallen out with one of the world's foremost Egyptologists, the director of the Egyptian Museum in Berlin, Dieter Wildung. Wildung allowed two Hungarian artists temporarily to fuse a 3,300-year-old bust of Queen Nefertiti to a modern bronze statue - based on an actual statue from the same period in the Berlin museum - to make a video installation for the Venice Biennale. It was attached to the statue for "only a few hours", but it brought an outcry from Cairo that Wildung had "defamed Egypt's history". Wildung - and his archaeologist wife - have now been denied permission to excavate in Egypt in the future, and told that no Egyptian official will co-operate with them in any capacity.
That is not all. The British Egyptologist, Dr Joann Fletcher, a mummification specialist from the University of York, recently announced that she may have found the mummy of Nefertiti, the stepmother of the legendary boy king Tutankhamun who ruled the Nile kingdom in the 14th century BC - and whose tomb, when it was discovered in 1922, became Egyptology's most famous find, containing so many artefacts that it took almost 10 years to remove them from the site.
Hawass reacted furiously to Fletcher's announcement. The British academic had found, in a tomb of the right period, a mummy with a long neck similar to Nefertiti's, as well as other physical links, including the impression of a tight-fitting browband (as the queen once wore), a double-pierced ear lobe and shaved head.
"Fletcher is a beginner and obtained her PhD only a short time ago and cannot, with her limited experience, judge such a discovery," Hawass fulminated. Foreign excavation teams who made incorrect announcements, he warned, would find their work stopped. One well-known British archaeologist has already been banned, according to the Cairo paper Al-Ahram.
In a world of high-octane academic rivalry there are those who complain - anonymously for fear of retribution - that the new antiquities chief hates the idea of foreigners getting the glory. Certainly he has said publicly that from 2007 foreigners are to be banned from starting new work at the prime sites of Giza and Saqqara. New excavations will be exclusively by Egyptian teams. Foreign experts will only be allowed to restore existing monuments there.
There was something threatening about the tone the Egyptian antiquities chief struck at the British Museum last week. Britain should voluntarily return the Rosetta Stone, he said, "otherwise I will have to approach them using a different strategy. There are various stages to our negotiations. I don't want to fight anyone now, but if the British Museum doesn't act, we will have to employ a more aggressive approach with the Government. I don't care if people know my strategy; the artefacts stolen from Egypt must come back."
Given the precedent of the Elgin Marbles, you might think he has the chance of a snowball in the Sahara. The 2,500-year-old sculptures depicting religious and mythological scenes, which once adorned the Parthenon in Athens, were removed around 1804 and brought to London by the British diplomat Lord Elgin. Athens has called for their return since 1829 without success - and Neil MacGregor has recently said that they will never be returned to Greece, even on loan.
As the Egyptian Antiquities department at the British Museum is perhaps the biggest and most important outside Cairo - illustrating every aspect of ancient Egyptian culture from pre-dynastic times (c4000BC) to the Coptic (Christian) period (12th century) - it might be supposed that it was immune from pressure. But the wife of its keeper of Egyptian antiquities, Vivian Davies, is the archaeologist Renée Friedman, who is the director of the American expedition to Hierakonpolis, the site of Egypt's first capital, where she discovered a full blown writing system in the pre-dynastic necropolis dating from 3500BC. Already there have been mutterings that Davies and Friedman could find themselves in the same position as Wildung and his wife.
On Hawass's shopping list, as well as the stone, are the bust of Queen Nefertiti from the Berlin Museum, the statues of Hatshepsut in the Metropolitan Museum of New York, and even the obelisk in the Place de la Concorde, one of the most famous landmarks in Paris, which he wants to restore to the Luxor temple, where it was originally one of a pair. And that is just the big stuff. He also wants a 5ft red granite statue of Alexander the Great from Frankfurt museum, as well as 17 items from Norway and four from Japan.
Under international agreements brokered by Unesco, governments have the right to recover antiquities stolen after 1971, but Hawass is also after artefacts such as the Rosetta Stone, which has been in the British Museum since 1802. It is not hard to see why the stone is top of his list.
On the face of it, the stone is just a compact basalt slab, less than 4ft long, on which is carved a text written by a group of priests assembled at Memphis on the first anniversary of the coronation of Ptolemy V as king of all Egypt. It was an attempt to emphasise in the eyes of the Egyptian elite the legitimacy of the 13-year-old king, whose dynasty was Greek but which had ruled Egypt since the fragmentation of the empire of Alexander the Great. So it listed all the good things that the pharaoh had done for priests and people. The list was to prove the key that unlocked the door to the mysteries of Ancient Egypt.
The stone was found in 1799 by French soldiers digging the foundations of an addition to a fort near the town of Rashid (Rosetta in English) in the Nile delta during Napoleon's expedition to Egypt. The stone was ceded to Britain under the Treaty of Alexandria in 1801, and the next year it was moved to the British Museum. There it puzzled cryptologists for decades.
What was unique about the stone was that it said the same thing in three languages. The first was in the pictograms known as hieroglyphs - the script of official and religious texts the Egyptians used for nearly 3,500 years. It was also in demotic - the everyday language of the time. Both of these no one could read. But it was also in the Greek used by the country's Ptolemaic rulers. Until the discovery of the stone, all attempts to uncover the secrets held by the ancient Egyptian hieroglyphics found on walls inside tombs had failed. The pictures were believed - wrongly - to be symbolic, each representing an object or idea.
But then Thomas Young, an English physicist who studied the stone, showed that the seven elongated ovals, or cartouches, in the hieroglyphic section spelled something phonetically - the royal name of Ptolemy. This suggested that hieroglyphs did not have only symbolic meaning, but that they also served as a "spoken language".
Gradually others built on his work. Finally, in 1822, the French scholar J-F Champollion worked out, cross-referring to modern Coptic, what the seven demotic equivalents were. Then he began tracing these demotic signs back to hieroglyphic signs, enlarging Young's list of phonetic hieroglyphs until he had laid bare the foundations of the ancient language.
It was, as a previous director of the British Museum, Graham Green, put it with forgiveable hyperbole, "the most important event of the second millennium". Which explains why Zahi Hawass is anxious to have the stone in his collection in Cairo.
The arguments against returning it are the same as those for hanging on to the Elgin Marbles. They can - in the words of Neil MacGregor, at the time when he ended discussions with a British campaign group seeking their return to Greece - "do most good" in their current home, where they can be seen in a broader historical context. "The British Museum is one of the great cultural achievements of mankind: it is very important that there is a place where all the world can store its achievements. I personally don't see any difference between Greek visual culture and the visual culture of Italy and Holland, which is also spread around the world," MacGregor said.
The Rosetta Stone is the centrepiece of the British Museum's Egyptology collection. If it were to be moved to the Cairo Museum, which has less than half the British Museum's number of visitors, it would be seen by far fewer people. Which is why the British are taking the same line on the Rosetta Stone as on the Marbles. "What curator in the British Museum would actually want to see leave an object that is absolutely core to our function as an institution?" the museum's Egyptian curator, Vivian Davies, has said.
But they can expect Zahi Hawass to fight tough. Within weeks of taking up his new office he created a new Department of Foreign Archaeological Missions, which has sent ripples of concern moving through non-Egyptian archaeologists. They are now required to submit a plan defining the borders of the excavation area, which cannot be subsequently extended. They are allowed only one excavation per season. They must now submit archaeological reports in Arabic as well as their own language. In the prime areas of Giza and Saqqara, they have to wind up their work within four years.
"Our policy is not to decrease the number of foreign archaeological missions in Egypt, nor to make things more difficult for them," Hawass told Al-Ahram, "but to control the excavations and encourage documentation, publication, restoration and conservation."
But foreign archaeologists are anxious. "We thought he was one of us until he got this job," said one, "but he seems to have gone power-mad; either that or he is exacting revenge for what he sees as slights in the past." (Hawass has been criticised by Dieter Wildung and others for starring in TV documentaries that use Hollywood clips and computer graphics).
The Egyptian himself is rather more philosophical. "If this [control of foreign archaeologists] is not done now, 100 years hence most of our marvellous monuments will be beyond repair," he has said. But he is emotional, too. When statues discovered in his excavations were sent, temporarily, to an exhibition at the Louvre, he said: "I was very sad that day because they were taking my children away from me." And he has offered a mystical justification, too. "We [modern Egyptians] are the descendants of the pharaohs. If you look at the faces of the people of Upper Egypt, the relationship between modern and ancient Egypt is very clear."
His government - his special backer is the President's wife, Suzanne Mubarak - sees in his cultural nationalism a tool to appease the discontent of Islamic fundamentalists who argue that Egypt is too pro-Western. One prominent Egyptian politician denounced Berlin's Nefertiti experiment as "un-Islamic", despite the fact that the queen co-ruled with the pharaoh Akhenaton, who changed Egyptian society to worship one god, the sun god, some 2,000 years before the Prophet Mohammed was born.
"Zahi Hawass is doing his job quite aggressively," said one British archaeologist, with considerable understatement. "The fear is," said another Egyptologist, "that Zahi has really got it in for foreigners and that in five years there will be no foreign-run digs in Egypt. He has said that he thinks that only about 30 per cent of Egyptian monuments have been unearthed, and he wants to make sure that the other 70 per cent are found by Egyptians. Meantime, he wants to get back as much as he can from foreign museums."
As he left to return to Egypt, Dr Hawass offered a compromise - "a possible three-month loan of the stone". Officials at the British Museum have publicly described the idea as "constructive". Privately, they fear they might never get it back.
Perhaps the loan should be reciprocal. The iconic golden death mask of King Tut could come west as the Rosetta Stone goes east. The idea of a hostage is, after all, one which should be familiar to anyone who knows the intrigues of that ancient land.