The tiny olive grove sits atop a dry canyon in the middle of the Negev desert, surrounded by barren hills and a few wisps of withering vegetation. Despite the parched setting, the ancient, gnarled trees are alive, their branches heavy with green leaves and ready to bear fruit.

Researchers believe these few trees, located a handful of kilometers outside the ruins of the ancient Byzantine settlement of Shivta, grew there through no fluke of nature. They may be among the last living witnesses to a complex civilization that built prosperous towns and farmed the Negev during the Byzantine period, more than 15 centuries before Zionists started imagining they could make Israel’s desert bloom.

Fresh research is shedding new light on these Byzantine desert dwellers – who were they? How did they shape their environment to such an extent? And why they ultimately, and quite mysteriously, abandon the lands they had fought for so hard?

Open gallery view Ancient olive trees growing on the remains of a Byzantine terrace a few kilometers from Shivta. Credit: Ariel David

Researchers say these questions are key not just for historians but for any society, including modern Israel, that wishes to develop and grow sustainably in an extreme environment like the desert.

“This was a complex society, so this question is very relevant to us, because the next time that the Negev was so densely settled was with Zionism and the creation of Israel,” says Haifa University archeologist Guy Bar-Oz. “It is very relevant for us to understand how they did it and what went wrong.”

From frankincense to farming

If we visited the central Negev 1,700 years ago, far from a barren wasteland peopled mainly by nomads and lizards, we would see a countryside dotted with farms and monasteries. Vast fields of grain, olive groves and fruit orchards lined the wadis; vineyards produced some of the most popular wines in the ancient world. There were also at least seven large towns supporting trade and agriculture in the area.

Although their remains are listed by UNESCO as World Heritage sites, archaeologists have barely scratched the surface in some of them.

The regional capital, Halutza – once the seat of a bishop, public baths, churches and a theater – has largely been left buried under the sand, mostly due to lack of funds and frequent looting by local Bedouins.

The second largest Byzantine town in the area – Ruheibe, also known as "Rehovot in the Negev" – has been partially excavated. But it is difficult to access, including because it is surrounded by an Israeli army firing zone.

Still, archaeologists have managed to glean some information about the people who lived there, says Uzi Dahari, deputy director of the Israel Antiquities Authority, who in January published an article on research in Ruheibe in the Israeli journal Kadmoniot.

Tribal population of Nabateans

The inhabitants worshipped in churches and wrote in Greek, the Byzantine empire’s official language. But the architecture of towns like Ruheibe – clusters of small houses and tight winding alleys to keep the sand out and provide shade – point to a local, tribal population, Dahari says.

Open gallery view column capital in the ruins of Ruheibe decorated in typical Nabatean style. Credit: Ariel David

The names on the tombstones of Ruheibe’s cemetery and the morphology of dozens of skeletons that were dug up, further indicates that most of the inhabitants were Nabateans, Dahari told Haaretz during a visit to the site.

The Nabateans were a semi-nomadic Arab people best known for building the spectacular rock-cut city of Petra and a trade empire that brought spices and luxury goods from the Orient to the Mediterranean. In fact, the Byzantine towns of the Negev started out in pre-Roman times as Nabatean trading posts on the spice route between Petra and the port of Gaza. Later they also profited from the passage of Christian pilgrims between Jerusalem and St. Catherine’s Monastery in Sinai.

Open gallery view Saint Catherine's Monastery Credit: REUTERS

So why would rich merchants, fat on the profits from selling frankincense and myrrh, decide to settle down and become farmers?

Open gallery view Petra, an ancient Nabatean city in today's Jordan Credit: Modi Epstein

“Imagine if we stopped using oil: what would happen to the Saudis?” says Dahari. “They could not go back to being nomadic shepherds, also because their numbers have increased, so they would have to use their money to create something else.”

How to capture the rain

And that’s probably what the Nabateans did. In the 3rd century C.E., the Roman empire underwent a political and economic crisis that disrupted trade routes. During the next two centuries, the fall of the Western empire and the spread of Christianity throughout the Mediterranean further reduced the demand for the luxury goods that the Nabateans had supplied.

“They could not move north, because during the Byzantine period, the Holy Land was very densely populated. So they had to settle and farm this land, possibly with the support of the Byzantine administration and outside experts,” Dahari explains.

The climate would not have been much different from today, with rainfall averaging around 100 millimeters a year, he says. So, their entire lives were centered on capturing and storing the rains that each year fall in the Negev during brief, violent showers.

The entire city was plastered and paved to channel water toward the cisterns dug in the courtyard of each house. Larger cisterns and open-air reservoirs were built in the surrounding countryside, along with wells that could reach the underground aquifer – up to 63 meters deep, like a 20-story building.

This system would have been just enough to provide water all-year round to satisfy the basic drinking and washing needs of the inhabitants, according to Dahari. But what about the fields?

Open gallery view An open-air reservoir outside Ruheibe, used to collect winter rain in the Byzantine period. Credit: Ariel David

For this, just around the town of Ruheibe, the inhabitants built 250 kilometers of terraces, dams and canals, using a vast 180,000 cubic meters of stone, according to a survey conducted by Dahari and his team. This system would be used to control the violent floods that usually follow the rare storms in the Negev. Instead of running off into the desert, the water would be channeled into the terraces, where it would soak the ground, helping to keep it moist for the rest of the year.

Importing parrot fish

Similar systems have been found around other settlements in the area, including at Shivta, where a solitary olive grove still survives atop a stone terrace which, judging from the pottery archaeologists found there, was built in the Byzantine period. (Scientists are still working to try to date the trees).

“Once this system is working, it can provide the equivalent of 500 millimeters of rain instead of the average 100,” explains archaeologist Yotam Tepper. “But it’s very labor intensive. It requires constant maintenance: if one dam is breached, one terrace is damaged, the water escapes, the ground doesn’t get soaked and you lose everything.”

Despite the backbreaking work required, from the 4th to the 7th century C.E., the communities of the Negev did not merely survive, they thrived. Locals could afford to import exotic goods, like parrot fish from the Red Sea, hundreds of kilometers away. Meanwhile, they shipped their produce, including fruits, olive oil and especially wine across the Mediterranean and beyond.

Open gallery view Parrotfish were imported from the sea to the desert. Credit: Ewa Barska, Wikimedia Commons

The distinctive amphorae in which the sweet, highly alcoholic wines of the Negev were packaged have been found as far as Italy, France and Britain, says Bar-Oz.

And then, almost overnight, it all ended.

If you walk through the streets of Shivta and other Byzantine desert towns you notice something strange about the crumbling houses: most of the entrances were neatly sealed with large stones.

It’s as if one day the inhabitants packed up their belongings, sealed their homes and left, never to return.

Why that happened remains a mystery, and is one of the key questions behind a project, led by Bar-Oz and funded by the European Union, to investigate the Byzantine Negev using advanced scientific methods.

Go north, young Nabatean?

Many theories have been put forward. It is however too early to draw conclusions, Bar-Oz says.

One preliminary study, based on dating samples from the ancient garbage dumps outside Halutza, suggest that organized refuse collection in the city abruptly ended around the year 540. This could point to a crisis connected to the Plague of Justinian, a pandemic that is estimated to have killed millions in Europe and the Middle East at that very time.

But there is little or no evidence in the area of mass graves or other signs of such a catastrophe, Bar-Oz notes.

Open gallery view A 63-meter-deep well dug near Ruheibe. The well still works and the grooves in the stones were left by ropes over centuries of use. Credit: Ariel David

Other data from the garbage dumps of Halutza indicates that as the years went on, locals used an ever-increasing amount of low-quality wood as fuel, which may suggest they were facing climate change.

Finally, one theory that historians have long favored, connects the decline of the Nabatean settlement of the Negev to the Muslim conquest in the first half of the 7th century.

Open gallery view A Greek cross decorates a door lintel in Shivta. Credit: Ariel David

However, there are few signs of violence and destruction in the Negev towns associated with the arrival of Mohammed’s followers. Many of the settlements, including Shivta, continued to be inhabited in the early Muslim period – albeit by a smaller population.

Dahari, the archaeologist who dug at Ruheibe, explains it all by theorizing that the Muslim takeover of the Middle East and the collapse of Byzantine control in the region meant the inhabitants of the Negev simply became freer to leave and seek greener pastures in more fertile areas of the Levant.

“You only live in the desert if you have to,” Dahari says. “The inhabitants here were Arabs, just like the new conquerors, so many probably converted to Islam and went north with their brethren.”