Dear Mar Shiprim readers,
This month we thank Prof. Mathieu Ossendrijver for sharing updates from the ZODIAC project funded by the European Research Council and hosted at Freie Universität Berlin. The ZODIAC project’s interdisciplinary approach seeks to develop an updated account of the emergence and cross-cultural impact of zodiacal astral sciences in Babylonia from the 5th century BCE.
With warm wishes for spring,
Pavla Rosenstein
Mar Shiprim Editor
In the Spotlight: Mathieu Ossendrijver on ZODIAC at Freie Universität Berlin
Can you please introduce yourself?
I started out studying Physics and Astronomy, but I’ve always been interested in ancient languages and ancient sciences. I developed an interest in Babylonian Astronomy after I discovered Babylonia as a topic and began to study cuneiform at the University of Utrecht while completing a PhD in Astrophysics. I then moved to Freiburg University for a postdoctoral role in Astrophysics, where I met Konrad Volk, who suggested applying for funding to enable me to continue to work on Babylonian astronomy for a second PhD in Tübingen. It took a few years to switch fields, but I’ve never looked back.
Mathieu Ossendrijver, project lead, ZODIAC (photograph by Lorenz Brandtner)
Can you tell us how the ZODIAC project started?
I wanted to apply for a five-year ERC (European Research Council) project covering ancient sciences in Babylonia, while I was still working on the TOPOI project at Humboldt University, exploring the relationship between spatial entities and knowledge in ancient civilisations. It took several months to narrow down the topic into researching the formation and transmission of ancient zodiac systems and then a relatively short three months to compile the official application. What made it easier was already having a full team of myself and three experienced postdoctoral researchers collaborating to apply for funding: Andreas Winkler, Michael Zellmann-Rohrer and Marvin Schreiber. Once we received funding, the team was expanded to include two PhD students: Thomas Peeters and Alessia Pilloni, and an Egyptology postdoctoral researcher managing our digital projects: Christian Casey.
Each team member has a specific area of focus. For example, Alessia Pilloni looks at knowledge transfer within Babylonia, while Thomas Peeters studies the accuracy of astronomical calculations between different cultures and how this can be mobilised to trace knowledge transfer through an increase or a decrease in accuracy and to what extent this may depend on skillsets developed in different regions.
We also have several other members who are not funded from within the ERC project but rather have chosen to conduct their research with us with external funding, for example Maria Teresa Renzi-Sepe, who completed her PhD in Leipzig and is funded by the German Science Foundation in order to investigate ancient knowledge of planets in the first millennium BCE.
I was further strongly advised by colleagues who had similar projects to hire an administrative professional and we have the perfect solution with Tanja Hidde who ensures that coordinating with both the European Union and the university goes smoothly. In this regard working with ERC funding is particularly helpful. Although we work closely with the university administration, we also have more freedom in terms of the hiring processes than if we were hiring directly from within the university.
The Zodiac team in 2024 (this photograph and below courtesy of the ZODIAC project)
The ZODIAC premises: Institute for History of Knowledge in the Ancient World (opening celebration 2021)
What are the project’s main goals and how have they evolved over time?
We try to create a convincing narrative of how and why the zodiac was transferred across multiple regions with different languages and different systems of social organization and religious beliefs: why and how was this possible specifically starting with the fifth century BCE in Babylonia? That is the ultimate goal of the project: to better understand how this rather peculiar set of practices connected to the zodiac – including the specialised computational techniques needed to create horoscopes – has spread so successfully that it became a global and lasting phenomenon that is still used today.
We are specifically looking at the first stage of this transfer of knowledge, a wave we can recognize in antiquity roughly between the fifth century BCE and the third century CE, by which time technical knowledge of the zodiac spread across the Roman Empire. Further waves of transmission could also be studied in Arabic, Byzantine and Sanskrit sources, although that is beyond our current scope.
The project is divided into stages, and the final stage we are now entering is about testing whether there is a connection between the emergence of multi-cultural empires and the spread of zodiac-related practices. One idea we have that continues to evolve is that this initial wave of knowledge transfer may correspond with the emergence of multi-cultural empires with a lot of movement of people, goods and practices between different regions, for example within the Achaemenid Persian Empire and later in the Seleucid, Ptolemaic, and Roman empires. These then appear to result in the development of political cross-regional structures and maybe also changing social needs and desires.
One could argue that in contrast to older methods of divination such as extispicy, the zodiac’s reliance on predictive mathematical calculations of planetary movements rather than direct observation of natural phenomena is more easily translatable across different languages and cultures, while lending the practice a specific type of new authority different from the more localised traditions connected to liver and wildlife observations.
The project site states that “zodiacal astral science emerged and was transmitted across the ancient world because it offered universally appealing, adaptable solutions to social, religious and political needs that emerged in multi-cultural empires.” Can you expand on that?
Divination – in other words the practice of predicting the future – is an almost universal technique that is found in many ancient cultures and of course frequently attested in Mesopotamia. We know about liver divination and celestial divination, for example, both of which were used by rulers as an instrument of their politics: kings could present their actions as legitimate and foretold in the stars. When horoscopy emerged in Babylonia, “non-royal” people seem to have taken up this idea, perhaps satisfying a new need for private divinations, a need for information and a sense of certainty. Once this celestial divination of telling the future from the stars moved into the personal sphere, I have the impression that this was taken up by different ancient cultures particularly in these multicultural empires where all kinds of new and varied social and political processes might have triggered the emergence of these new needs.
Such social phenomena would of course need to be studied in more detail through sociological and anthropological research, bearing in mind the problem of anachronism. There is a lot of research, for example in how innovation and technologies spread within the field of history of technology, but it’s not always applicable to the ancient world. Similarly, a large amount of valuable literature has been generated in the last fifteen or twenty years on modern and ancient empires and multiculturalism, but one must be careful when applying these models to specific regions.
The project utilizes a range of ancient sources in different languages. How do you manage the inter-disciplinary needs of the team?
From the onset we decided that we will be an intensively collaborative group, based in a physical location rather than working remotely. Some of us know about cuneiform texts, others about demotic and papyri sources, so we need a lot of interaction to understand from each other what is going on across the different regions we are studying. For that reason it is important to have a physical working space that fosters organic interaction and spontaneous conversations. We also have a weekly research meeting where we discuss each other’s research or read a paper or a chapter from a book on any topic connected to our project, and we learn a great deal through these meetings.
As well as engaging with existing literature, we are working on several unpublished primary sources, particularly in the field of late Babylonian astrology, which is both a focus area for Marvin Schreiber and something we examine together as a group. These first millennium BCE texts held at the British Museum have been incompletely studied as many of them are fragmentary with only a few copies. While a few of the tablets are well known and have been edited, for example the so-called calendar and micro-zodiac texts where each tablet covers two signs of the zodiac (sometimes including drawings – for example VAT 7847), we are now producing more completed editions. We are also endeavouring to make joins where possible, collaborating with the Fragmentarium project in Munich. Further important texts that have not been intensively studied come from the Greek papyri and a large number of astronomical sources from Egypt written in demotic. These texts have the potential to informs us about how later standard astronomical and astrological handbooks from the Greco-Roman world, for example the Tetrobiblos and Astronomica (Manilius) came into existence, since they contain a number of similarities to Babylonian astronomical practices, but without direct references.
Detail of the seleucid calendar text for the Leo zodiacal sign (VAT 7847 at the Vorderasiatisches Museum, Berlin)
What is the ZODIAC glossary project and the Bibliography of Mesopotamian Astral Science (BibMAS)?
We set up the ZODIAC glossary in part as a research tool for us, and we utilise it frequently throughout our work, discussing new terms that we manually add to the database. We specify how each term corresponds to different versions of it in different languages and where it can be found and in which kind of text. It was important to us to make the glossary public so that anyone can use it, and while it is still in development, we decided to publish it at an early stage so that it can become useful for other scholars.
Currently there are thousands of terms in Akkadian, Latin, Greek and Demotic as well as smaller subsets in Hebrew, Latin and Sanskrit. These cover zodiac signs, planets, technical terminology for calculations, and astrological doctrines. We recently added an advanced search feature, so that one can also search for a category like “planet” and see all the lemmata for planets, while ruling out or isolating specific languages. Later this year we are aiming to add a feature where terms or categories can be selected to create a specialist glossary list that can be extracted as a PDF.
The BibMAS database is an expanded and updated version of the Bibliography of Babylonian and Assyrian astronomy compiled by Christopher B.F. Walker together with the 2004 website Bibliography of Mesopotamian Astronomy and Astrology by Robert van Gent. The Bibliography is publicly accessible via Zotero and intended to provide an up to date literature guide for those interested in the sub-field.
Landing page of the ZODIAC glossary project, which can be accessed at https://zodiac.fly.dev
What’s next in terms of publications and public-facing events?
Individual publications are listed on the ZODIAC website , including a set of nice discoveries such as those featured in Alessia Pilloni’s IAA prize-winning article published in JNES, where she convincingly identifies at least two new meanings for the frequently used astrological technical term bīt niṣirti (“house of secrets”) depending on the text genre. I will also shortly be publishing an article that expands on the meaning of this term in Greco-Roman texts, whereby outdated Babylonian degree locations for specific stars that correspond to bīt niṣirti are still used in Greco-Roman planet exaltations. Both Alessia’s and my findings were discovered in our regular team meetings, underscoring the importance of intra- and inter-disciplinary collaborations within the project. We are also working on publishing our workshop proceedings later this year and several monographs are in the works: Andreas Winkler has written on Demotic astrological handbooks, Marvin Schreiber on Babylonian astrological texts, and Michael Zellmann-Rohrer on Greek astrological papyri.
Finally, I am happy to share that we have started to work on an exhibition at the Neues Museum in collaboration with the Pergamonmuseum in Berlin, slated to open in 2026. The exhibition will focus on the zodiac in the ancient world, and we will be able to exhibit artefacts such as Babylonian cuneiform tablets, gems with depictions of constellations, sun dials, papyri and Egyptian ostraca that are already housed in Berlin. We were fortunate to receive an extension from the ERC to complete the ZODIAC project in 2026 specifically so we can work on staging the exhibition, which will also bring the project closer to public audiences at its conclusion.
For more information about the ZODIAC project, visit: https://www.geschkult.fu-berlin.de/en/e/zodiac/index.html
Interview by Pavla Rosenstein