VIDEO: When was the Tomb of Christ discovered?

Over the centuries, Jerusalem’s Church of the Holy Sepulchre has suffered violent attacks, fires, and earthquakes. It was totally destroyed in 1009 and subsequently rebuilt, leading modern scholars to question whether it could possibly be the site identified as the burial place of Christ by a delegation sent from Rome some 17 centuries ago.

Now the results of scientific tests provided to National Geographic appear to confirm that the remains of a limestone cave enshrined within the church are remnants of the tomb located by the ancient Romans.

Mortar sampled from between the original limestone surface of the tomb and a marble slab that covers it has been dated to around A.D. 345. According to historical accounts, the tomb was discovered by the Romans and enshrined around 326.

View Images A restorer removes debris beneath a broken marble slab to expose the original rock surface of what is considered the burial place of Jesus.

Photograph by Oded Balilty, AP for National Geographic

Until now, the earliest architectural evidence found in and around the tomb complex dated to the Crusader period, making it no older than 1,000 years.

While it is archaeologically impossible to say that the tomb is the burial site of an individual Jew known as Jesus of Nazareth, who according to New Testament accounts was crucified in Jerusalem in 30 or 33, new dating results put the original construction of today's tomb complex securely in the time of Constantine, Rome's first Christian emperor.

The tomb was opened for the first time in centuries in October 2016, when the shrine that encloses the tomb, known as the Edicule, underwent a significant restoration by an interdisciplinary team from the National Technical University of Athens.

Several samples of mortar from different locations within the Edicule were taken at that time for dating, and the results were recently provided to National Geographic by Chief Scientific Supervisor Antonia Moropoulou, who directed the Edicule restoration project.

When Constantine's representatives arrived in Jerusalem around 325 to locate the tomb, they were allegedly pointed to a Roman temple built some 200 years earlier. The Roman temple was razed and excavations beneath it revealed a tomb hewn from a limestone cave. The top of the cave was sheared off to expose the interior of the tomb, and the Edicule was built around it.

A feature of the tomb is a long shelf, or "burial bed," which according to tradition was where the body of Jesus Christ was laid out following crucifixion. Such shelves and niches, hewn from limestone caves, are a common feature in tombs of wealthy 1st-century Jerusalem Jews.

The marble cladding that covers the "burial bed" is believed to have been installed in 1555 at the latest, and most likely was present since the mid-1300s, according to pilgrim accounts.

When the tomb was opened on the night of October 26, 2016, scientists were surprised by what they found beneath the marble cladding: an older, broken marble slab incised with a cross, resting directly atop the original limestone surface of the "burial bed."

Some researchers speculated that this older slab may have been laid down in the Crusader period, while others offered an earlier date, suggesting that it may have already been in place and broken when the church was destroyed in 1009. No one, however, was ready to claim that this might be the first physical evidence for the earliest Roman shrine on the site.

Is This Really The Tomb Of Christ? Scholars discuss whether the tomb of Christ is actually the tomb of Christ and how it would have looked.

The new test results, which reveal the lower slab was most likely mortared in place in the mid-fourth century under the orders of Emperor Constantine, come as a welcome surprise to those who study the history of the sacred monument.

"Obviously that date is spot-on for whatever Constantine did," says archaeologist Martin Biddle, who published a seminal study on the history of the tomb in 1999. "That's very remarkable."

During their year-long restoration of the Edicule, the scientists were also able to determine that a significant amount of the burial cave remains enclosed within the walls of the shrine. Mortar samples taken from remains of the southern wall of the cave were dated to 335 and 1570, which provide additional evidence for construction works from the Roman period, as well as a documented 16th-century restoration. Mortar taken from the tomb entrance has been dated to the 11th century and is consistent with the reconstruction of the Edicule following its destruction in 1009.

"It is interesting how [these] mortars not only provide evidence for the earliest shrine on the site, but also confirm the historical construction sequence of the Edicule," Moropoulou observes.

The mortar samples were independently dated at two separate labs using optically stimulated luminescence (OSL), a technique that determines when quartz sediment was most recently exposed to light. The scientific results will be published by Moropoulou and her team in a forthcoming issue of the Journal of Archaeological Science: Reports.

Secrets of Christ’s Tomb premieres Sunday December 3 at 9/8c on the National Geographic Channel. The immersive, 3-D exhibition " Tomb of Christ: The Church of the Holy Sepulchre Experience" is open at the National Geographic Museum in Washington D.C. through the fall of 2018.