That is a vital quality in the complicated and sometimes dangerous world of Middle Eastern archaeology. When the Baath Party of Saddam Hussein took over in Iraq in 1968, “heads and bodies were displayed in the square near our home, and we had to make detours so the children wouldn’t see them,” Oates recalls. The family moved the next year from Baghdad to London so David could take a professorship at an archaeology institute. In the mid-1970s, David decided that he wanted to tackle Brak, which lay just across the Iraqi border in Syria but was nevertheless part of Mesopotamia—the storied lands around and between the Tigris and Euphrates rivers. The dramatic site of Brak had been briefly excavated by Mallowan in the 1930s, but Christie found it not to her liking, since rainfall was too sparse for the flowers she loved to grow; they split their time with another ancient mound farther north with a slightly wetter climate.

Brak was in the archaeological boondocks. Virtually all the action during previous decades had focused on southern Iraq, in the low-lying alluvial plain that merges with the Persian Gulf. Work there had uncovered enormous ancient cities dating back to 3000 B.C. and even earlier. Mallowan worked at Ur, the legendary birthplace of Abraham, where he met Christie and helped his mentor Leonard Woolley excavate royal tombs dating to 2500 B.C. German archaeologists found the fabled metropolis of Uruk, celebrated as the place where writing originated and where the famous King Gilgamesh reigned; Uruk appears to have been a bustling metropolis by 3500 B.C. Nearby were the ruins of Eridu, viewed by the Sumerians themselves as the world’s oldest city. These ruins yielded evidence of a small building, possibly a temple, dating to 5500 B.C.

The silt laid down by thousands of years of floods coupled with the frequent rebuilding of these sites in ancient times made it difficult to penetrate down to their origins. So we know precious little about how Sumerian cities began to evolve. By contrast, much if not all of Brak sits above the floodplain. That makes its earlier levels more accessible, theoretically. In the course of his dig here, Mallowan had uncovered a mysterious building he called the Eye Temple, for its thousands of unique votive objects with flat, trapezoidal bodies and thick necks topped with pairs of huge eyes. He also found evidence of richly decorated copper and gold work as well as small clay cones painted on their ends to adorn walls. This was a style popular in distant Uruk in the centuries after 3500 B.C., so Mallowan assumed the edifice was a southern concoction. He did not suspect that under his feet was evidence of an urban society independent of ancient Sumer, and at least as old.

Arriving at Brak in 1976, Joan Oates wanted to explore the period before 3500 B.C. to see if settlement there predated the influx of southern influence. But her husband vetoed the plan as too risky. A huge mound like Brak is no simple wedding cake, with early layers below and later layers above; rather, it is a mind-bogglingly complicated mass of jumbled history. Wind and rain have had their way with the site in the 3,000 years since it was completely abandoned. Broken pottery bits have drifted down slopes, mixing with earlier potsherds. Foundations have vanished in sudden flash floods. A stone throne sits overturned in a deep gully, far from where its royal occupant once sat. Try to reach an early layer, David Oates knew, and you might find yourself exhausting both your time and money before you hit pay dirt.

And money has been a perpetual source of anxiety at Brak. The British School of Archaeology in Iraq and, later, the McDonald Institute at Cambridge University have supported the dig, but the Oates team has had to be frugal. Team members live in canvas tents during the spring and fall seasons—stifling on the frequent hot days, and uncomfortable at night when temperatures can plunge to near freezing. Only this year did electricity arrive.

So Joan patiently bided her time as she and her husband excavated the rich upper layers of the high mound. Then one day in 1981, her son spotted signs of a thick-walled building just below the surface on the northeast end of Brak, and her husband began to dig along what proved to be a fortification from the second millennium B.C. But in one corner of the excavation, Joan discovered bits of pottery dating back a thousand years farther. “I said, ‘This is where we can get at the fourth millennium B.C.,’” she recalls. This time her husband agreed.

It took a decade of arduous work on a steep section of the hillside to carve back through the centuries. Even the 2004 death of her husband did not halt Oates’s efforts. One morning, as if we are setting out for a stroll through the English countryside, she takes me on a walk across the mound to the massive wedge-shaped hole she and a generation of archaeologists and local workers have carefully made, its back wall soaring more than 30 feet. A slight woman in an off-white windbreaker, Oates pauses in the trench and peers around. She looks annoyed. “You are seeing here only a fraction of what’s going on, a little window on the economy of the past,” she says. “It’s terribly frustrating.” But even that small fraction that she and her team—made up largely of Syrian, American, and British excavators—have found is nothing short of revolutionary.

One of the most dramatic discoveries at Tell Brak is a large building with massive redbrick walls and ovens nearly 10 feet across. The types of pottery found, along with radiocarbon analysis of ash deposits, date the building to about 3800 B.C. By contrast, few large structures have been found from a time before 3500 B.C. in southern Iraq. Scattered across the building’s floor was a varied collection of objects, from large piles of raw flint and obsidian from Turkey to finished blades. All about lay an array of beautiful stones collected and stored for making beads: jasper, marble, serpentine, diorite. The site also contained a large chunk of bitumen, a valuable tarlike substance used to bind stone or wood, which had to have been imported from eastern Iraq or Turkey. Mother-of-pearl inlays lay cut and ready to be placed in jewelry. The remains of sheep and goats abounded, as did spindle whorls, probably used to make yarn, and simple looms—all clear signs of weaving activity.

Among the most notable artifacts unearthed was a lavish, black-and-white chalice, its cup made of obsidian and its base of white marble, the two held together with bitumen. The rim of the cup showed evidence that it had been overlaid with a valuable metal such as gold, long since removed. Whoever owned the chalice clearly held great power. Nearby was a piece of clay bearing a large impression of a beautifully carved striding lion, a symbol of royalty even today. Amid a pile of mass-produced bowls were potsherds with marks similar to the pictographs that show up more than half a millennium later in the first writing system, cuneiform. Those marks may be the earliest evidence of writing anywhere in the world. “The development of symbols may have a long history in southern Mesopotamia too,” Oates says. “But we just don’t have the evidence there.”

Beneath the redbrick building, Oates and her team found a more modest one dating to about 4000 B.C. This earlier structure was a center of craft production on a large scale and was also a busy site of communal cooking, judging from its huge ovens set next to plastered basins and bins. Just outside ran a street paved with pottery shards, headed for what Oates believes was a north gate facing the resource-rich mountains of Turkey.

Next door, Oates uncovered a large edifice with a massive basalt threshold and thick walls, entered by passing through two small rooms, perhaps guardhouses. She believes this is the oldest administrative center yet known. Nearby, the excavators found bits of clay stamped with lion and snake motifs, seals that signified ownership of property, and a statuette with large eyes. At the Eye Temple, the site of an earlier dig on the southern side of the mound, Oates found signs that the earliest structure here dates back to about 3800 B.C. And nearby, in another trench, her team found traces of a brick platform and a wall built 1,000 years before that.

These excavations prove that Tell Brak was a place of impressive wealth and sophistication, an important trading center and a major (and previously unappreciated) player in the early game of civilization. It even had suburbs. Oates invited a team of American archaeologists to examine the area beyond the high mound, which covers only about one-fifth of the site’s nearly 750 acres. The remainder lies within the halo of smaller mounds circling the site. By methodically sampling the area inside and outside this halo—a laborious task of mapping, examining pottery, and digging small test pits—the researchers concluded that Brak covered 320 acres in the period between 3900 and 3400 B.C. Some 20,000 people may have lived within the city limits, and dozens of smaller sites lay within a 10-mile radius. And this large population—only Uruk in southern Mesopotamia is thought to have been as large in this era—was supported without any irrigation.

So is Brak the world’s earliest well-documented city? There is no accepted definition of what constitutes a city, Oates points out. But the size and elaborate nature of the site certainly put it on or near a par with its southern rivals. “I would never say Brak is larger than Uruk,” she says. “But there is clearly a complex society developing in the north that is independent of the south.” Jason Ur, a Harvard archaeologist who participated in the suburban survey, adds that all the evidence “surely qualifies Brak as urban, if that term is to have any meaning.”

Ur (coincidentally sharing the name of the famed southern Mesopotamian city) was the first to jump into the trench made by that backhoe in 2006 at the small mound just north of Brak’s central hill. But it was left to Arkadiusz Soltysiak, a Polish bioarchaeologist, to sort through the human bones. He found no infants and few elderly and determined that some of the victims had suffered traumatic injuries, as might come from a blow by club or mace, that had already healed before they were killed. The incomplete, scattered skeletons made it hard for him to establish the gender of the victims, but surviving teeth hinted at a population of adolescents and young adults. Some of them also appear to have suffered from malnutrition.

Soltysiak leans toward the theory that this event at what locals call Tell Majnuna was a massacre, noting that some of the bones are from people not of warrior age. If so, it could have been an inside job. Others think the dead might have been locals who rebelled or otherwise offended the city’s elite, were put to death, and then were denied decent burial. But Augusta McMahon, who is the Brak dig’s field director, argues that the scene more closely resembles an attack. “The age profile, the piles of bodies, and the rubbish context says battlefield cleanup,” she tells me as we trudge through green wheat fields from the high mound to Majnuna. “And the corpse abuse—the way they were haphazardly piled up, the way femurs were made into tools—says the victims were enemies of whoever buried them.” One possible scenario, she says, is that Brak’s enemies attacked from the outside and managed to kill some civilians in the melee before being routed.

In either case, nabbing food or finished goods may have been a motive for the bloodshed. (Two years ago, grain shortages during a drought led to riots in this part of modern-day Syria.) Brak’s obvious concentration of wealth would pose a temptation to outsiders.

Soltysiak and McMahon agree on what happened next. The victors or perpetrators left their victims on the field for weeks or even months. The rotting corpses were eventually hauled to the shallow depression at Majnuna and unceremoniously dumped. The total body count is clearly in the hundreds, though for now excavations there have ceased. About 10 yards from the mass grave, the team found another cache of bones that are probably the result of the same incident: mostly skulls and femurs, stacked in relatively neat piles. Two dozen of the femurs were whittled at one end to a point, perhaps to dig around in the skulls of the dead, but for what purpose is unknown. Soltysiak recalls being startled to discover the human bones that had been made into tools here.

Then came a massive feast. Mixed on top of the death pit were the bones of cows, sheep, and goats along with broken plates. “The animals were cut in about the same place on a large scale, in an industrialized way,” says Jill Weber, the team’s zooarchaeologist. “Not necessarily by the same person, but in the same way.” In her mud-brick laboratory on the mound, she pulls out massive scarred cow bones. Such wholesale slaughter would have been unusual, she says, particularly the slaughter of cows, which were typically considered too valuable to kill because of milk production and plowing. “No expense was spared,” Weber says. “This was an important event.”

And it was just the start of a series of violent acts that shook ancient Brak. Back at Majnuna, McMahon points out another mass grave, dating to a century or so later, adjacent to the first pit. One clump of bones looks as if it had been piled into a bag that decayed. Just a few yards away is another mass of human bones, dating to about 3600 B.C. The victims in both slaughters appear to be young, the skeletons are jumbled, and there are no grave goods, which would have been typical in a formal burial.

Along with the bones are all manner of refuse, such as broken pottery and flint tools. Majnuna seems to have been one of Brak’s main dumps. One possibility is that the waves of enemies who threatened the city—whether rebellious locals or foreign raiders—were treated like garbage. As we step off the mound, the man who owns the area containing the mass graves pulls up in his new GM pickup. “Come for breakfast!” he insists with typical Arab hospitality. As we walk down the dusty road to his home, he pulls a gun from his holster to admire it.

Violence at the dawn of civilization was not unique to Brak. An hour’s drive to the east is Hamoukar, which was a thriving settlement during the early and mid-fourth millennium B.C., around the time that Brak arose. Echoing the sophistication of its neighbor, Hamoukar had well-planned houses with courtyards, large ovens, seal impressions in the form of lions killing deer (a style seen at Brak as well). Recently a joint Syrian and American team found evidence of a battle around 3500 B.C. in which Hamoukar buildings were destroyed.

This attack may have been more than an incursion by marauders looking for food or goods. At that time, the southern city of Uruk began to expand its influence, and Uruk-style pottery appears throughout the Middle East. Possibly those southerners ran into opposition from the formidable northern settlements of Hamoukar and Brak, whose inhabitants may have resented the growing power of Uruk and its allies. Brak and Hamoukar were burned around the same time, but “evidence of both northern and southern material suggests a peaceful coexistence afterward,” Oates says. “The ‘destroyers’ could well have come from Anatolia or anywhere else.” By 3400 B.C., pottery typical of Uruk predominated, and Brak’s Eye Temple had been renovated in a southern Mesopotamian style. When Brak appears in the historical record in the third millennium, it is as the important city of Nagar. Overwhelmed by superior technology, better military organization, or a persuasive new ideology, the pioneering civilization at Brak and its environs became an adjunct of the south, which went on to create even grander city-states, bureaucracies, and empires.

Violence and cultural sophistication may in fact have gone hand in hand in creating the first urban societies. “Tell Brak is not just another archaeological site but a place where new aspects of humanity emerged, and our work has the potential to explain them,” Ur says. Finding answers in Iraq may not be possible for a very long time, given the political troubles there. This gives the exploratory digs in Syria a special urgency.

Brak’s independent advances in the north came to an abrupt end, but perhaps not a dead end. Maybe the interaction between the two competing visions, whether through trade or warfare (or both), helped spur the innovations that changed our world. “Civilization spreads like a virus. It happens in clusters and not in isolation,” says Guillermo Algaze, an archaeologist at the University of California at San Diego. In the past decade, excavators have begun to find evidence to support this idea around the globe. A thousand years after Brak lost its independence, an astonishing array of urban sites sprang up across the Iranian plateau, central Asia, and the Arabian Peninsula. In the following 1,000 years, a host of interacting cultures contributed to what emerged as Chinese civilization.

In exposing one of the world’s earliest experiments in urban living, Oates and her team are illuminating both the creative and violent tendencies of humanity and painting a much richer picture of how our species left the country for life in the city, a process that is still in full swing today. “In textbooks you learn that civilization starts with Sumer, and everything else is peripheral,” says Algaze, who was once an outspoken advocate of the dominance of the south. “But Brak shows a picture more complex than that. It has forced us to think differently.”

Eyes peeled, Oates continues her push to dig even deeper into Brak’s past. “She’s brilliant—and she’s changed the field,” Algaze says. “And she’ll get to those earlier levels.” Unlike her old friend Agatha Christie, Oates is after bigger game than a single murderer. In the ultimate whodunit of civilization, the ancient people of Tell Brak were, at the very least, important accomplices.