We have long known that some of the builders in antiquity had extraordinary skills, but still don’t know how certain monumental construction projects were achieved. Now at least, though, one mystery has been put to bed: How the ancient Romans achieved efficiency in their massive construction projects, whether building roads or edifices from scratch.

Their stonemasons carved or painted small, all-but-imperceptible instructions onto the stones themselves, explain Arleta Kowalewska and Dr. Michael Eisenberg of the University of Haifa’s Institute of Archaeology, in the journal Tel Aviv.

Much of their work was done in Antiochia Hippos, as the Romans called the city, set upon a hill overlooking the east of the Sea of Galilee.

“Following the research at Hippos and around the region, we realized for the first time that the marks from the quarries can be dated to the massive construction of Herod the Great, and then tend to disappear,” Eisenberg tells Haaretz. “They appear again only within the great Pax Romana and boom of construction in the Roman East. The cities in our region needed a large-scale quarrying effort to fulfill the need for building blocks and architectural elements for the public and for monumental construction.”

Thus, Eisenberg and Kowalewska have shown that in this hilltop town, the practice of carving or painting masons’ marks began in the late first century and ended in the late second century. There are other places where it began earlier and ended later.

“Now, archaeologists who lack datable material can use the marks to narrow down the date of a single architectural fragment and even a structure, using — with caution — the suggested dating frame,” Eisenberg adds.

Open gallery view One of the basalt drums of Hippos' colonnaded street, with a masons’ mark (which would have been hidden from view) Credit: Dr. Michael Eisenberg

Another block in the wall

Construction in Hippos (Sussita in Aramaic) and other towns throughout ancient Israel, Jordan and Syria and beyond was not done by laying identical, industrially manufactured bricks like we do now. Then, stone blocks had to be carved out of the bedrock individually. In Hippos, that bedrock was basalt.

And it wasn’t that one set of numbskulls whipped by overseers knocked blocks out of bedrock, then another set transported them (with or without quadrupeds), then a third set mindlessly erected walls out of identically shaped stone (ashlar) blocks. Creating stone blocks and building with them was skilled work.

Open gallery view Section of a column as masons marked them Credit: M. Eisenberg

Evidently, report Kowalewska and Eisenberg, the stonecutters of yore craved acknowledgement. Who doesn’t?

They also aspired to ensure that the builders would put the blocks and pieces exactly where they were supposed to go during construction. Both purposes were achieved with masons’ marks.

Open gallery view Hippos' decumanus maximus - main street, with masons' marks on its basalt pavers Credit: Dr. Michael Eisenberg

Some 2,000 years later, give or take a few centuries, the marks — tiny and often concealed to begin with — are barely discernible. Finding them takes eagle eyes, technology, a flashlight and an idea of where to start looking.

In fact, the marks had gone largely unremarked until Eisenberg and the team began to partially reconstruct a Roman basilica at Antiochia Hippos.

“The penny only dropped after we had already rebuilt some of the heavy basalt drums comprising the Roman basilica’s columns,” Eisenberg says. “Each column had been as much as 9 meters [nearly 30 feet] tall, and was made of a pedestal, base, shaft and, finally, the capital, all made of locally quarried basalt.”

The rub was, the drums of the columns all shared the same diameter but differed in height. So, the order of the drums had to have been planned back at the quarry: Each was marked to show where it should be placed within the column. “The piece marked ‘IIIIA’ went above ‘IIIA,’ and so on,” Eisenberg explains.

Open gallery view The Hippos forum, after the rain, with a view of the Sea Of Galilee. About 20% of the basalt paving stones bear masons’ marks Credit: Dr. Michael Eisenberg

Thus, the colonnaded main street of Hippos-Sussita could be reliably reconstructed — a first in the annals of local archaeology.

They didn’t need to mark every single block: about one in five was enough. Some of the marks were letters; other were symbols; some were both. Back then, literacy was not to be taken for granted.

Once you set out to look for them, you discover that masons’ marks existed in ancient towns built of stone blocks throughout the Levant. They peaked in the Roman period, which was indeed characterized by massive construction projects.

Open gallery view Mason's mark from the stables, Montfort Castle Credit: Adrian Boas

At the biblical site of Megiddo (known in Christian literature as Armageddon), masons’ marks appear as small letters or even just shapes engraved on stone blocks used in the walls and streets. The stone blocks and paving stones in the main street of ancient Hippos-Sussita also bear numerous little engravings, the team tells Haaretz.

Hidden spots of Montfort Castle — a massive Crusader structure in the Upper Galilee that defended absolutely nothing — also feature stones with little carved designs.

All isn’t vanity

So the masons’ marks were of two fundamental types: signature and instruction. “Ancient stonemasons were as fussy about credit as any Hollywood starlet, it seems,” observes Kowalewska. At least some of the markings on the stone blocks in ancient Israelite towns, and Roman cities too, seem to have been personal signatures.

Open gallery view Mason's mark on a basalt drum, part of the basilica colonnade Credit: Dr. Michael Eisenberg

Was this just vanity? Probably not. “Building stones start in the quarry,” Kowalewska explains. Lacking modern machinery, men broke their backs extracting and preparing the stones. But knowing where to place and angle the wedge took skill, as did striking it properly to break pieces from the bedrock. “Then they had to carve usable architectural elements out of it by hand,” she says. The stonecutters were, in two words, muscle-bound artistes.

The carved or daubed marks weren’t necessarily the individual mark of a single person. A given team at a given quarry would have a given mark.

Open gallery view Mason's mark Credit: A. Kowalewska

In Kowalewska’s opinion, a key reason masons “signed” their blocks was to make sure they got paid, assuming they weren’t slaves, and so that no one else could steal the credit for their work.

And as the team realized at Hippos, ego and recompense aside, the marks also served as early assembly instructions — akin to the “instructions” Ikea provides with its flat-pack products, Eisenberg says.

Brought to you by the letter Heh for Herod

Looking at the gorgeous large columns that decorated the cities of Rome and Greece, they were comprised of multiple parts. Before being moved from the quarry to their destination, the pieces would be carved to fit with one another as they would sit in the final edifice. Why? Because transporting finished pieces with all the extraneous material knocked off is easier and lighter, and therefore cheaper, Kowalewska explains.

Masons in the quarry marked the pieces so the builders at the construction site would know how to assemble them. For example, under one system, each part of the column would be marked with a letter and a number — the letter symbolizing the column, the number the position within that column.

Once construction was done, the instruction marks were sometimes entirely concealed from view. For instance, marks on the column parts at the Propylaea (the monumental gateway to the Acropolis in Athens) were engraved on the covered face of the stones.

Often, the masons’ marks would consist of letters. “That can establish the provenance of the workers,” says Kowalewska. “Marks on King Herod’s palaces and tomb are in Hebrew, indicating involvement of local stonemasons, although the buildings themselves have many Roman features.”

At Hippos-Sussita, about 20 percent of the heavy basalt stone-block flooring bears masons’ marks. “We managed to identify 20 different types,” Kowalewska shares. “It is entirely possible that the quarriers couldn’t read or write, but they did know how to make their marks.”

Also, the marks can be a tool for reconstruction of buildings, providing they are preserved on many of the stones. If the marked stone has been reused, they can tell from which structure it was taken. Besides their usefulness for archaeologists, these marks also serve as a simple reminder of all the hard work undertaken by the builders of the past.

The Roman-period mausoleum at the Hippos necropolis — a grand structure with multiple stories that is presently undergoing excavation — contained dozens of magnificently designed stone parts that all bear masons’ marks. “Maybe one day we will be able to reconstruct it as it really was, based on the masons’ marks,” Eisenberg says.

Maybe they will, if they learn not only to find the marks but to read them too.

Sussita National Park is managed by the Israel Nature and Parks Authority.