Biblical Archaeology Review 36:2, March/April 2010

New Evidence of the Royal Stoa and Roman Flames

By Aryeh ShimronOrit Peleg-Barkat

Orit Peleg-Barkat of the Hebrew University has been studying the hundreds of elegant fragments that fell from the Royal Stoa on the herodian Temple Mount in Jerusalem when it was destroyed by the Romans in 70 C.E. In the course of her research, she came across some unusual-looking stones, so she consulted leading Israeli geologist aryeh Shimron to help her understand them. We’ll start with Orit.

The historian Josephus gives us our most detailed description of the Herodian Temple Mount prior to its destruction by the Romans in 70 C.E. Before rebuilding the Second Temple, Herod doubled the size of the previously existing Temple Mount. In the center of the nearly rectangular platform was of course the Temple, facing east.a “To approaching strangers,” writes Josephus, “[the Temple] appeared from a distance like a snow-clad mountain; for all that was not overlaid with gold was of purest white.”1 On the eastern, western and northern borders of the Herodian Temple Mount were lovely columned porticoes.

On the southern end of the Temple Mount was the magnificent Royal Stoa, which, Josephus tells us, was “more worthy of description than any other [structure] under the sun.”2 Consisting of a basilica across most of the length of the southern wall, the Royal Stoa had four rows of magnificent Corinthian columns, creating three aisles, a wider one in the center and narrower ones on either side. The columns were 27 feet high. The elaborate decoration of the edifice with its columns and entablature, says Josephus, “caused amazement by the magnificence of its whole effect.”

On the Temple Mount side, the Royal Stoa was open. On the other side was a wall. From the roof you could look down into the valley below, where most of the finds I will describe were found. The distance from the roof down to the valley was so great that if you looked down from above you would become “dizzy” or “giddy,” according to Josephus (depending on which translation you use3).

It is obviously not possible to excavate on the Temple Mount, so we shall probably never know what archaeological remains are buried there. From 1968 to 1978, however, Professor Benjamin Mazar of the Hebrew University excavated the area outside the southern wall of the Temple Mount. Unfortunately, he died in 1995 without completing his final report. Since then, the task has fallen to his granddaughter, Eilat Mazar, also of the Hebrew University. She has already published several volumes, and she invited me to study the more than 400 architectural fragments found in the destruction debris below the southern wall of the Temple Mount. This became a major part of my doctoral dissertation, which is now proceeding to publication.

From these architectural fragments, many of which came from the Royal Stoa above, we can get a visual idea of its architectural decoration. Of course, only the stone, not the wood, decorations have survived. Josephus tells us of “deeply cut wood carvings representing all sorts of different figures” that decorated the ceiling of the Royal Stoa, but these would have been completely burned in the fire. And even the surviving stone fragments are not abundant, for reasons we will describe.

The fragments that did survive are all carved in local whitish-to-beige and gray-colored limestone and include column bases, column drums and several types of capitals, architraves, friezes, cornices, ceiling decorations (soffits) and door frames. The carving is fine and delicate and constitutes an enormous variety of floral and geometrical motifs.

Despite their fragmentary state of preservation, the assemblage represents one of the largest and richest Second Temple Period assemblages ever found. It allows a glimpse of the splendor of the buildings erected by Herod on the Temple Mount and exhibits the work of the best artists in Jerusalem.

Although many of the fragments come from the Royal Stoa, some are from the western and eastern porticoes on the Temple Mount. Other fragments may come from the tower at the southwestern corner of the Temple Mount or the entrance to the Royal Stoa at the top of the monumental stairway (above Robinson’s Arch) on the western side of the Temple Mount.

The architectural fragments were either retrieved from the destruction debris at the foot of the enclosure wall of the Temple Mount or were incorporated in secondary use as construction material in later walls from the Byzantine and Umayyad periods. The architectural fragments suffered from the effects of the destruction and the conflagration of the Temple compound in 70 C.E., and also from their reuse by later builders.

The largest of the hundreds of fragments that have been recovered include such architectural elements as a column base 3 feet in diameter; similar-sized column drums; Corinthian capitals, Doric friezes and modillion cornices. Most of these can be confidently assigned to the Royal Stoa.

Some of the architectural fragments have parallels in the contemporaneous local architecture of Jerusalem, as can be seen in public buildings and funerary monuments of the time. Some fragments, however, reflect unique architectural characteristics. For example, the cable pattern carved on the astragal at the bottom of the Corinthian capitals (see photo at the beginning of this article) finds its parallels in the Hauran and is clearly an eastern motif. The design of the acanthus leaves on modillions (cantilevers) on some of the cornices originates in Rome. All of this points to the unique character of the Temple Mount architectural decoration, combining features of east and west, as well as local architecture.

While I felt fully confident in my analysis of the character of the architectural fragments, I was not equipped to analyze the fine white crust and other geological features that appeared on many of them. Was this a kind of plaster covering put there in ancient times? Or was it a kind of exfoliation that developed as a result of the debris having been burned and then buried for two millennia?

I decided to consult a leading Israeli geologist who was an expert in ancient plaster, Aryeh Shimron:

When I first examined Orit’s specimens, many of them did seem to have been plastered, perhaps for decorative or architectural purposes. But when I examined thin sections under an optical microscope, it became obvious that the story was far more complex.

Limestone, which is the common building stone in Jerusalem, is a marine sedimentary rock. Examination of these thin sections under the microscope revealed tiny fossils of marine flora and fauna that continued directly from the limestone into the gray discoloration. In addition, tiny veinlets of clay-ey material referred to as stylolites could often be seen continuing uninterrupted from the limestone into the white crust.

Continuities of geological features from rock into plaster could not possibly occur if the latter was manmade since the plaster would be young and the geological features are very ancient.

If not manmade, then how did this plaster-like white crust covering the limestone form?

The white crust is approximately 1.5 centimeters thick. The limestone directly beneath this crust has been discolored. Instead of the original white-to-buff color of Jerusalem limestone, it passes into a dark gray toward the outer surface. This gray discoloration is due to the assimilation of soot on the rock surface. Soot is a fine dust formed from the incomplete combustion of wood. During conflagration soot was absorbed from smoke into the outermost surfaces of limestone masonry. When subjected to further burning at temperatures above at least 800 degrees centigrade (1470 degrees Fahrenheit) for a sufficient length of time, the soot burned off and the now-clean outermost limestone surface converted to white quicklime (calcium oxide, CaO, the basic ingredient in making plaster). Any soot remaining behind would be seen as a gray substratum beneath the white outer crust.

Since, in time, quicklime reverts back to the mineral calcite (CaCO3, the main constituent of limestone) it will be seen as a white crust that may still retain some of the original lime which can be identified by X-ray diffraction techniques.

Transformations such as those above take place at a minimum temperature of about 800 degrees centigrade, at which limestone converts to lime, but conflagration temperatures may rise to even 1200 degrees centigrade (2200 degrees Fahrenheit) at which time certain materials may be converted to glassy substances.

The process we have just described may also explain another curious feature of the excavation of this area, namely the lack of significant burnt remains. The likely explanation is this: Quicklime absorbs moisture from the air, which causes it to swell, resulting in shattering, flaking and finally the disintegration of the limestone. Few burnt remains were found in the excavation because the burned stone was so badly damaged, or crumbled to dust, that it would have been cleared out during the 2,000 years since the destruction.

Naturally, there are many variations to what I have just described. One is manifested in the change in the color of limestone masonry and architectural fragments passing from its natural beige to a pinkish and finally gray discoloration different from that described above. In this case the color variation is not due to assimilation of soot but due to chemical changes in the clay and iron minerals in stylolite veinlets that cut the limestone. Iron minerals in particular reveal an excellent visual record of burning: They change from hydrous water-bearing yellow to anhydrous pink and finally gray-colored, reflecting mineral phases.

One of the most intriguing varieties of architectural fragments recovered in the excavation was a limestone rosette. In this case it was made of buff-to-pinkish limestone. However, the surface is spotted with reddish-brown sand-size chips. When I examined these chips by X-ray diffraction, they could be identified as the mineral apatite. And apatite comprises the main crystalline phase of bone! This architectural fragment was covered with a veneer of burnt bone dust.

The reddish-brown bone chips were welded onto a yellowish-white frothy substratum that covered the architecturally worked gray surface of the rosette. This yellowish-white substratum was the result of vitrification, forming a kind of glass: The reddish-brown bone chips on the surface had been fused with the surface of the limestone rosette, a process that implies a temperature of at least 800 degrees centigrade.4

A scanning electron microscope (SEM) confirmed that the internal fabric of the sand-size chips was bone. I cannot tell, however, whether the bone is animal or human. One cannot help wondering: Was this all that is left of some human being caught in the conflagration so dramatically recorded in the Josephus Flavius narrative? Or was it the bone of some animal sacrificed before the Temple? Or some animal eaten by a pilgrim? Questions like this, of course, can never be answered.

What we can say, however, is that the color, morphology and mineral changes revealed in our examination of the fragments are clearly a product of a long-sustained, high-temperature burning.