New Study of Roman Ballista Stones Confirms Josephus’s Account of the Siege of Jerusalem

Archaeological discoveries reveal the eyewitness account—surprise, surprise—to be spot-on. (And as an aside: Does the Bible reveal the origin of such machines?)
Kfir Arbiv, Israel Antiquities Authority excavation director, cleans a ballista stone.
Yoli Schwartz/Israel Antiquities Authority

The first-century c.e. Jewish historian Josephus has had his fair share of detractors—including those who challenge the veracity of his eyewitness accounts of Jerusalem during his day. But thanks to newly released archaeological research in the lead-up to this year’s Tisha B’Av (the commemoration of the fall of the temple), archaeologists have found significant corroboration for Josephus’s account of the 70 c.e. Roman siege against Jerusalem—namely, the precise positioning of the Roman “ballistae” siege engines.

Illustration of a Roman ballista
Pearson Scott Foresman

Israel Antiquities Authority (iaa) archaeologist Kfir Arbiv presented his computer-based findings in a press release Sunday. His focus has been on recording the precise locations of Roman military equipment discovered on various excavations in and around Jerusalem. Especially prominent are the hundreds of ballista stones (rounded, semi-large stones launched by a sprung catapult system—see image, right). These ballista stones could be launched distances up to nearly half a kilometer via ballistae (also known as “bolt throwers”) at their intended targets. Arbiv also noted the findspots of launched bolts/spearheads and infantry slingstones, as well as general equipment.

Different sizes of ballista stones
Kfir Arbiv/Israel Antiquities Authority

“With the help of the computer, I located all the ballista [stones] exactly where they were found,” stated Arbiv, whose work constitutes part of his MA thesis for Tel Aviv University.

I took into account the local topography and the location of the Second Temple-period city fortification walls, and I made ballistic calculations, including the launching angle, and the throwing distance of the stones. All the data was compared to the renowned Jewish historian Josephus’s contemporary detailed descriptions of the battle, and the conquest and destruction of Jerusalem, in his book, The History of the Jewish War Against the Romans.

Clara Amit/Israel Antiquities Authority

As the Times of Israel’s Amanda Borschel-Dan noted, “By taking measurements of the absolute height of the in situ ballistics and the use of a computer algorithm, Arbiv said he was able to prove that the radius of the fallen stones’ launches corresponded to Josephus’s described 300–400 meters.” Arbiv stated, “It is extremely exciting to be proving the narrative of Josephus onsite.”

A major concentration of ballista stones was discovered at Jerusalem’s Russian Compound excavations. “This is not surprising,” Arbiv noted, “as whoever controls this spot dominates the whole area and the fate of the city. This aligns with Josephus’s account that Titus commanded to penetrate the city from the northwestern side of the city wall.” Through this part of Jerusalem ran the “third wall” described by Josephus, which was breached by the Romans. At least hundreds (and perhaps thousands) of ballista stones were scattered through this area.

The Russian Compound excavation site. Note the ballista stones scattered across the ground.
Yoli Schwartz/Israel Antiquities Authority

Other “hotspots” of Roman siege machines include areas within the center of Jerusalem, including Nahalat Shiv’a. Different sizes and weights of ballista stones also tell their own stories—heavier stones were launched against walls with a view toward penetration, while smaller stones were used against enemy infantry.

The Russian Compound excavation site
Yoli Schwartz, Israel Antiquities Authority

As iaa Director Eli Eskosido summed up: “The physical evidence of the huge resources employed by the Roman army in Jerusalem, reflect the extremely harsh battles that eventually led to the destruction of the Second Temple.” He continued:

Notwithstanding the internal factions and the impossible odds, a small group of Jewish defenders withheld the Romans for a few months until the tragic destruction of the city. The use of up-to-date research methods reveal more and more on the fascinating history of Jerusalem.

One final side note of interest: These ballistae, which could launch both stones and iron bolts, played a crucial role in the Roman overthrow of Jerusalem. Yet is it possible that such ingenious slinging devices were originally the brainchild of early Jewish inventors? The Bible suggests just such an “invention”—using that very terminology.

The earliest form of ballista is typically attributed to the Greeks of the fourth century b.c.e. Yet 2 Chronicles 26:15 describes the eighth-century b.c.e. King Uzziah overseeing the construction “in Jerusalem [of] engines, invented by skilful men, to be on the towers and upon the corners, wherewith to shoot arrows and great stones.”

Ballista against the ruins on the ancient city of Gamla, Israel
Oren Rozen
Let the Stones Speak