Two thousand years ago, in a Jerusalem buzzing with life, Jewish potters worked around the clock producing pots, jars and stands, as the industry was fueled by a population whose adherence to religious purity laws created an increasing need for clay vessels. New research by Israeli archaeologists has shed light on this flourishing activity as well as on the dramatic changes brought by the destruction of the Temple and of the city, as the industry progressively passed into the hands of the Romans.A team of experts from the Israel Antiquities Authority analyzed several pottery workshops uncovered in excavations conducted in the area of the modern Jerusalem International Convention Center and the Crowne Plaza Hotel, revealing how materials and techniques employed, products manufactured and even the identity of those ancient artisans were deeply affected by the historical events in the area. The findings were published in the May 2020 issue of the Bulletin of ASOR – The American Schools of Oriental Research. “The site we considered is one of the largest pottery workshops in the eastern Mediterranean,” Dr. Anat Cohen-Weinberger, co-author of the paper with Danit Levi and Dr. Ron Be’eri, told The Jerusalem Post. “The workshops were active for about 300 years between the Hasmonean and the Middle Roman periods in the second century CE.”Cohen-Weinberger heads the IAA Petrographic Laboratory, which has been operating for about 30 years. Petrography aims at studying and identifying rocks and minerals and allows to ascertain their geological source, which helps archaeologists to collect important insights on ancient pottery and its manufacturing.“Our research has been based on the regular archaeological tools, such as studying architectural plans and the distribution of production facilities, as well as on the petrographic study of the ceramic vessels and building materials found in the site,” the scholar explained. “All of them revealed that a significant change occurred after 70 CE.”Cohen-Weinberger pointed out that before the Temple was destroyed by the Romans in 70 CE, the potters operating the workshops were Jewish and the organization of the workshops was compatible with industrial production of private manufacturers.During that period the production boomed, an event that researchers generally associate with the fact that Jewish purity laws, which played an essential role in Jewish life at the time, increased the need for clay vessels, since clay vessels were extremely susceptible to ritual impurity and very hard to purify, likely creating the demand for new objects.“Clay vessels... can be rendered and render [objects] impure in its interior space; and render impure by [contact] with its exterior, but do not become impure by [contact] from its outside; and their breaking [if they are impure] is their purification,” reads the second chapter of Mishna Kelim (translation Sefaria.org).After 70 CE, new pottery types typically associated with Roman legions, such as building materials like roof tiles and bricks, started to be produced side by side with cooking vessels and other vessel types, Cohen-Weinberger said. “The kilns were authorized by the Roman army and operated for them, most probably still by Jewish potters.”Furthermore, a new clay recipe began to emerge. While potters were still using clay and mud from the nearby Moza formation in the Judean Mountains as in the previous period, quartz grains started to be mixed with them, increasing the toughness of the clay and the resistance of the products.“There is no quartz in the proximities of Jerusalem,” the archaeologist said. “The source of the quartz used has not been determined yet, but it mostly likely came from the coastal dunes some 50 km away. This attests the effort spent to collect raw materials and it fits well with the power and organization of the Roman army.”Between the two Jewish Revolts in the first half of the second century, the Roman army took over the pottery workshops and started operating them directly.“The spread of the Roman rule in the area is reflected in broad categories of material culture, including in the ceramic production, whose processes and products became similar to the ones uncovered in other legion camps in Europe,” Cohen-Weinberger explained.“Archaeologists have been looking into the settlement of Roman legions in Jerusalem for a long time and have not yet found the exact location of their camp,” she added. “Every piece of information on the legions and on their connection to the Jewish population is therefore very important.”The researcher highlighted how their findings on pottery recipes and techniques might help connect buildings and settlements emerged in many excavations in the Jerusalem area to the 10th Legion stationed in the city, as well as provide insights on its activity.“We are already running several studies of ceramic building materials uncovered in several sites,” she concluded.