More than a decade ago, archaeologists began to excavate one of the world's oldest Christian churches in the middle of a forbidding Egyptian desert. Delayed by war, political unrest and a global pandemic, the dig has turned out to be a revealing and confounding look at how early Christians buried their dead.

Built on an oasis sometime in the fourth century, the church held a surprisingly large number of corpses: 11 bodies in two crypts and six in separate tombs. Typically, in that period, leaders like priests and bishops would have been buried in a church, while others would have been relegated to cemeteries. But in this desert outpost, most of the remains belonged to women and children.

"The fact that there are so many tombs right inside the church is remarkable," said David Frankfurter, an Egyptian religion scholar at Boston University who was not involved in the project.

Whereas ancient Egyptian funeral practices tended to be lavish and grandiose, early Christian burials favored simplicity. The bodies in the church were wrapped in linens, and only two were inside coffins. Bundles of rosemary, myrtle and palm leaves were left with one body, and one child was buried with a bronze cup. Otherwise, the tombs were sparse.

The team -- led by David Ratzan, a scholar of ancient civilizations at New York University, and Nicola Aravecchia, an archaeologist at Washington University in St. Louis -- began excavations at the church in 2012. But political upheaval, as well as the accidental killing of several tourists by the Egyptian military in a nearby area of the Western Desert, kept the researchers out of Egypt for many years. Only in 2023 was the team allowed to return to Egypt and finish its work, as described in a book published in September.

The church stood on the eastern edge of Trimithis, a large city where thousands of people lived. The excavations there have also uncovered a villa, a pagan temple and a Roman bathhouse, all erected in what the archaeologist Richard Long called "one of the most barren and hostile environments on earth."

In the late fourth century, Trimithis was abandoned. But because of its remote location, the city generally avoided large-scale development. Layers of sand preserved the city for nearly two millenniums.

Although Trimithis was remote, its robust production of dates and olives allowed residents to trade with people in the fertile lands along the Nile River. A middle-aged woman buried in the church had all her teeth intact, possibly evidence of a good diet and a life of relative comfort, despite the harsh surroundings. "It was much more interconnected to the world than one at first might guess," Dr. Aravecchia said of the city (which is called Amheida today).

The rectangular, colonnaded structure of the church, for example, adhered to the basilica style that was then popular in Rome -- a sign that the Roman design sensibility had arrived in Trimithis in just a few years.

"You have the same architecture deployed for public churches in the middle of a village in the middle of nowhere," Dr. Ratzan said.

The Roman emperor Constantine converted to Christianity in A.D. 312. The desert church was built a few decades later, as Christianity rapidly grew in popularity.

The surprising findings in the crypts beneath the church suggest that Christian doctrine remained open to interpretation as it was embraced by millions of people in the Roman Empire.

"It's an interesting and uncomfortable moment for the church," Dr. Ratzan said, with the once-revolutionary religion trying on the trappings of officialdom.

Though millions had taken up the new faith, there was still room to experiment, including in how to think about death. "People are concerned with the corpse, not with resurrection or with soul," Dr. Frankfurter said of the Trimithis church. That would run counter to the prevailing idea that Christianity was more occupied with the spirit than the body when it came to the afterlife.

The preponderance of female corpses is also intriguing, experts said.

"We have ample evidence that women held leadership positions in ancient Christianity," said Laura Nasrallah, an expert in early Christianity at Yale University. Dr. Nasrallah cautioned that she did not yet know enough about the Trimithis church to say whether the women buried there may have been religious officials.

Archaeology often involves trying to piece together a coherent story from clues that tug in different directions. "I think we should have the courage to speculate," Dr. Ratzan said.