CAMBRIDGE — Tunneling deep below ground, archaeologists with a joint Harvard University/Museum of Fine Arts excavation team knew they were onto something big. It was 1925, and after weeks of clearing a burial shaft at Giza, Egypt, they had an unprecedented find: the undisturbed tomb of Queen Hetepheres, an Egyptian royal who lived some 4,500 years ago.
"They get to this little unfinished room, and except for this alabaster sarcophagus it's just a big pile of stuff," said Peter Der Manuelian, director of the Harvard Semitic Museum. "All the wood is gone, flooded, eaten by insects, gold is collapsed, hieroglyphs have fallen, furniture has come down, ceramics are broken."
Now researchers at Harvard have used advanced computer modeling software to re-create a key discovery from that tomb, which they say is the most luxurious known piece of royal furniture from Egypt's Old Kingdom: Hetepheres's throne. It goes on public display at the Harvard Semitic Museum in Cambridge on Thursday.
"There is furniture from this period and even older, but nothing like this in terms of ornateness," said Der Manuelian, adding that most of the known royal Egyptian furniture is from the New Kingdom, about 1,000 years later. "It is a unique discovery."
Led by the famed archaeologist George Reisner, the original excavators spent two years belly-down on mattresses as they used tweezers to collect each fragment from the tomb, roughly 100 feet below the earth's surface. They took nearly 2,000 photographs of the crypt and filled thousands of pages with careful notes, documenting the dimensions, materials, and location of each shard.
Conservators and craftsmen used those notes to re-create some furniture from Hetepheres's tomb in the 1930s; those replicas now reside at the Cairo Museum and in storage at the Museum of Fine Arts.
The new throne, however, is vastly more complicated. Crafted from cedar, wrapped in gold foil, and boasting intricate ceramic inlays of falcons, flagstaffs, beetles, and arrows, it is the equivalent of a 3-D puzzle with more than 2,300 individual pieces.
"This is experimental archaeology," said Rus Gant, lead technical artist on the project. "We wanted to know how they made it, not just replicate something that looked like it. This is a data-driven model: the same wood, the same cuts, the same faiences," or glazed ceramic inlays.
Of course, there were some minor differences in the fabrication process. The Egyptians didn't have a computer-driven 3-D milling machine to carve the throne's cedar body, for instance. Nor did they have computer modeling software to keep track of each piece of the puzzle.
"In theory, the pieces would fit beautifully," said digital artist David Hopkins, who created the 3-D computer model for the chair. Nevertheless, he said, they ended up doing "a lot of sanding."
Still, the researchers, who used the excavators' documentation and estimate the project took roughly 1,000 hours to complete, are confident that aspects of the building process closely mirror techniques of the original craftsmen.
"The sequence is wood, gilding, punch holes though the gilding where the feathers are, and put the faience pieces in," said Der Manuelian, who is also a professor of Egyptology. "We feel pretty good about that being the ancient sequence."
Researchers added that fabricating the throne's faiences was particularly challenging. Rather than cut individual tiles, they eventually landed on a technique of using a mold.
"We tried many different chemical combinations, different firing temperatures, we played with mold ideas," said Kathy King, director of education for the Ceramics Program at the Office for the Arts at Harvard. "I almost went to a psychic."
The throne is an initiative of the Giza Project at Harvard, which aims to create a digital archive of all known archeology from Giza.
Using excavator notes, diaries, photographs, maps, and other documents, the Giza Project has more recently moved into 3-D visualization, crafting virtual recreations of the historical sites.
"Rus came up with the original concept," Der Manuelian recalled. "We do all of this virtual reality, 3-D modeling — let's go back in the physical world and make this thing, because the people who made the other sets of chair reproductions couldn't. This is far fancier."
But if Hetepheres's throne has provided certain clues about craftsmanship and life in ancient Egypt, it also presents new mysteries.
"Some of the symbolism doesn't occur elsewhere, so why it's on this chair and what's the relationship to the queen is still under research," said Der Manuelian, who noted that the falcons on the arms of the throne are normally associated with kingship and the god Horus.
Also curious is a frieze of false beards along the back of the throne, as well as emblems representing the goddess Neith.
"All of these things are known, but they are not common furniture elements," said Der Manuelian.
Hetepheres was the mother of King Khufu, builder of the great pyramid at Giza, and the wife of King Snefru, first king of the Fourth Dynasty.
"It's interesting to look at this furniture and think what the back story is," said Der Manuelian. "Was it all made for the queen in life? For the queen in death? Could some of it have been originally for her husband who was king?"
Perhaps the biggest mystery occurred when the original excavators removed most of the smaller artifacts from the tomb and finally opened the sarcophagus that should have housed Hetepheres's mummy.
"They were rather shocked," said Der Manuelian. "They lifted the lid, and it was completely empty."