Near the ancient city of Marib, in Yemen, lies the ruins of a great dam. Considered to be one of the biggest engineering wonders of the ancient world, the Great Dam of Marib stretched for 580 meters and was easily one of the largest dams of its era. For as long as it stood, the Great Dam turned the desert into an oasis allowing the irrigation of more than a hundred square kilometers of sandy soil centered around Marib, which was then the largest city in southern Arabia. When the dam collapsed in the 6th century, it brought down this ancient commercial empire. The collapse of the Great Dam and the destruction of Marib was such an important event in the history of the region that it even finds a place in the Koran.

Ruins of The Great Dam of Marib. Photo credit: George Steinmetz

The city of Marib was the seat of power of the kingdom of Saba, known in the west as Sheba, whose legendary queen, the Queen of Sheba, is said to have visited King Solomon in Jerusalem with a caravan of valuable gifts of gold and spices. Although there is no evidence outside of the Bible that the queen even existed, the lavish present that she supposedly brought the wise King would be in keeping with the wealth of the Sabean monarchy.

The kingdom of Saba grew its wealth through trade along the Spice Route (also known as Incense Route) between southern Arabia and the port of Gaza on the Mediterranean Sea. Marib was one of several layovers along the route where merchants would stop to rest and exchange goods. Marib traded two rare and expensive products highly prized in the ancient world—the aromatic resins, frankincense and myrrh, that was cultivated from the sap of trees grown across the Arab world. Frankincense and myrrh were used by the ancient Egyptians in embalming, by the Chinese as medicine, and were burned for their aroma in temples and in imperial courts throughout the known world.

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The trees that produce frankincense and myrrh are extremely drought-resistant. Nevertheless, the trees need to be carefully tended just like any other agricultural crop, and along with date palm, they provided the broad base of the Sabaean economy.

Resins of frankincense. Photo credit: AmyLv/Shutterstock.com

To make agriculture possible in the desert, the Sabaeans built an extensive irrigation network consisting of wells and canals. At the centerpiece of this system stood the Marib Dam. Made of mortar and stone, the dam spanned across a large ravine that cut through the Balaq Hills by the Wadi Adhanah. According to modern estimate, the dam stood 15 meters high and was more than a half a kilometer long. It probably had a humbler beginning when it was first built somewhere between 1750 and 1700 BC. It was only in the 7th century BC, that the dam began to take massive shape with large stone and mortar abutments on dam’s north and south end connected to substantial stonework on either side of the river. These stone abutments still stand today.

The dam was maintained for centuries by successive generations of Sabaeans and later, by the kings of the Himyarite Kingdom after they succeeded the Sabaeans. The Himyarites undertook further reconstruction, raising the height of the structure to 14 meters, and built spillways, sluices, a settling pond, and a kilometer-long canal to a distribution tank. These extensive works continued until the 4th century AD. By then, however, Marib had lost its market for frankincense and myrrh to the rising faith of Christianity, which, during its initial years, forbade the use of frankincense because of its associations with pagan worship. As trade fell, Marib began to lose its prosperity.

Ruins of The Great Dam of Marib. Photo credit: Dennis/Flickr

The Great Dam that made the desert fertile and enabled the region to flourish, fell into disrepair. The sophisticated techniques of hydraulic engineering that the Sabaeans were famous for were slowly forgotten, and maintenance of the dam became increasingly difficult. Consequently, from the middle of the 5th century onwards, the dam began to suffer regular breaches until the year 570 AD, when the dam gave away for one last time.

There is much debate what caused the dam to collapse. Some scholars say it was heavy rains, while other believe an earthquake undid the stonework. According to legend, the breach was caused by large rats gnawing at it with their teeth and scratching it with their nails. While according to the Koran, the collapse was an act of God punishing the Sabaeans for their ungratefulness. The holy scriptures says:

There was for Saba' in their dwelling place a sign: two gardens on the right and on the left. "Eat from the provisions of your Lord and be grateful to Him. A good land, and a forgiving Lord. But they turned away, so we sent upon them the flood of the dam, and we replaced their two gardens with gardens of bitter fruit, tamarisks and something of sparse lote trees."

With the collapse of the dam, the irrigation system failed and the population—estimated to consist of some 50,000 individuals—migrated to other areas of the Arabian Peninsula. Today, Marib grows no more than a little wheat and, during the rainy season, some sorghum, sesame and a kind of alfalfa fed to animals. The old city is largely in ruins, and although a modern city has sprung nearby, it is a mere shadow of its former self.

Ruins of The Great Dam of Marib. Photo credit: Dennis/Flickr