Traditional and Modern Rulerships of the Decans
By Loaiza Pérez Heredia
From the Latin Decanus, meaning “chief of ten,” the Decans in the context of astrology today are an equal, no-nonsense subdivision of the 360° zodiacal wheel into 10° subsections, leaving three Decans per sign. Now, where did the decans come from, what is their purpose, and how can they offer any valuable context to the practice of astrology today?
First, we must understand their origins. With the same thirst for knowledge of the stars as the Babylonians and Mesopotamians, Egyptians began to count and section the sky into equal parts to track the positions of different fixed stars as they rose through the eastern horizon (rising degree) each day, as well as to track time. Eventually, as Egypt made contact with the aforementioned societies, the decans and the 12 zodiac signs merged.
In an interview on The Astrology Podcast hosted by Chris Brennan, Austin Coppock, author of the book 36 Faces, said:
“They’re very old. We see evidence of the decans being used and holding a lot of cultural importance in the 22nd or 23rd century BCE on coffin lid text. So we know that they were important enough in and in wide enough use and held in high enough regard that they would find their way into the tombs of kings by then. Which means that’s probably not when they were invented, right? By the time you’ve got hard evidence of something, it’s been around for a while.”
With time, the decans began to describe more than a division between fixed stars, but something about how each sign projected itself outwards. Throughout time, they were referred to as a given sign’s “face.”
Chaldean (Traditional) Decans
Henry Beston.“Herbs and the Earth. Garden City, N.Y. Doubleday, Doran 1935.
The decans were attributed to one of the seven traditional planets, in what we know as the Chaldean order. The Chaldean order is an ancient understanding of how the sky worked and moved. Assuming that each of the 7 wandering stars were contained within their own “sphere,” the seven visible planets were ordered from slowest to fastest-moving, in descending order. Each was assigned to one of the 36 decans, circling through the zodiac.
Let’s start with Aries, the point of the Spring Equinox. Aries’ first decan is ruled by Mars, since it’s Aries’ ruler. Its next decan is the Sun, the next fastest-moving planet in Chaldean order, followed by Venus, faster than the Sun. In Taurus’ decans, the first is Mercury, Moon, and then Saturn, circling back to the slowest-moving planet. On and on, like a merry-go-round.
Firmicus Maternus, a Roman astrologer and Senator, had this to say about the decans:
“…and they lay bare their dominion and authority over the ten portions. They do however have unlimited power and unlimited free license, and mark out the fates of men through the authority of their power.”
In this way, the traditional decans seem to function as a secondary storytelling aid in explaining the cyclical passage of time. However, as is natural with humankind, the tradition has begun to shift and change. The three outer planets Uranus, Neptune and Pluto have been discovered, leaving many astrologers to wonder where and how we can fit these elusive planets into our daily practices and systems.
Modern Decans
To the best of my understanding, the Modern decans were proposed by Alan Leo in the 20th century, though it’s not fundamentally understood why this was proposed, or the rationale behind it. In a shift from the tradition, Alan Leo proposed a new system, integrating the three outer planets Uranus, Neptune and Pluto to form part of the faces of the signs.
The biggest difference between the Chaldean and Modern system is that the first decan of each sign is its domicile lord. That is, Aries’ first decan is still Mars whereas Taurus’ is Venus, Gemini’s is Mercury, and so on, except for Scorpio (Pluto), Aquarius (Uranus), and Pisces (Neptune), which are their conceptualized domiciles.
Let’s see the differences between the two systems using two chart examples.
Example #1: Julius Robert Oppenheimer
Note: Rodden Rating DD
Chaldean Decans (example below)
Modern Decans (example below)
Julius Robert Oppenheimer was an:
American theoretical physicist and science administrator, noted as director of the Los Alamos Laboratory (1943–45) during the development of the atomic bomb and as director of the Institute for Advanced Study, Princeton (1947–66). Accusations of disloyalty led to a government hearing that resulted in the loss of his security clearance and of his position as adviser to the highest echelons of the U.S. government. The case became a cause célèbre in the world of science because of its implications concerning political and moral issues relating to the role of scientists in government.
To start, Oppenheimer’s ascendant is found in Gemini III following the Chaldean Decans, ruled by the Sun, and in Uranus’ face according to the Modern Decans.
Austin Coppock writes of Gemini III in his book 36 Faces the following of this Decan, calling it “An Executioner’s Sword”:
This decan teaches of life-or-death decisions, asking those who walk this face to bear their weight. Martial power and excellence in judgment result in those who can. Yet this face also teaches levity, the dual revelation of life as comedia/tragedia. For the wise laugh even as the executioner’s blade descends.
Most notably, Oppenheimer was known not only for his contributions to science but how they escalated to represent the death of millions of people. The inventor of the atomic bomb, a weapon of mass destruction, is very fitting for the nickname for this particular decan.
On the other hand, of Uranus, Mychal Bryan says:
Uranians are people who are before their time. They see the world around them differently than everyone else and may become outcasts because of this perspective early in life. People don’t understand their way of viewing things. They tend to think in a big way that is even larger than Jupiter can handle. Uranians see a completely new way in which the world can be run and are often trying to usher the world in that direction. They can be brilliant thinkers, savants, and capable of a level of problem-solving that leaves people awed. However, they can also be very erratic. Uranian people have been given life experiences that haven’t left them with the most stable relationship to the world and the people in it.
According to a Wired article on J. Robert Oppenheimer:
As he witnessed the first detonation of a nuclear weapon on July 16, 1945, a piece of Hindu scripture ran through the mind of J. Robert Oppenheimer: “Now I am become Death, the destroyer of worlds.”
Example #2: Albert Einstein
Note: Rodden Rating AA
Chaldean Decans (example below)
Modern Decans (example below)
According to Britannica, Albert Einstein was a:
German-born physicist who developed the special and general theories of relativity and won the Nobel Prize for Physics in 1921 for his explanation of the photoelectric effect. Einstein is generally considered the most influential physicist of the 20th century.
Einstein was most notable for his theory of general relativity, which he first published in 1915. Using the Chaldean decans, his chart falls in Cancer II, ruled by Mercury, whereas in the Modern decans, it falls in Pluto’s face.
Austin Coppock writes of Cancer II in his book 36 Faces the following of this Decan, calling it “A Walled Garden”:
In the first decan of Cancer the tender and fearful bonds of intimacy are established, and in the second the fragile duad is incubated. In this face come images of beauty, joy and wealth— for these emerge naturally out of a matter properly nurtured. Yet nurturing is insufficient —what is precious must also be protected. The second face of Cancer is like a walled garden in which something precious is kept. A greenhouse exists here, to nurture what is beautiful and exotic— but fragile.
According to an article from the BBC, “Albert Einstein found sanctuary in the cabin on Roughton Heath, near Cromer, Norfolk, for three weeks in 1933 after fleeing the Nazis.” Here, he was able to continue his work, albeit in a limited way. During his journey towards safety, many people contributed to keeping Einstein both safe and protected so he could continue his work.
Albert Einstein and Commander Locker-Lampson in 1933. From https://www.bbc.com/news/uk-england-norfolk-59401006
On the other hand, this is what Mychal Bryan has to say about Pluto in his book Mastering Traditional Astrology:
Plutonians come into this world with a deep sense of isolation, power, and severity. Plutonians have to learn very early in life the lessons of power and powerlessness. Very often, because of early powerlessness, the Plutonian seeks to have power over others later in life. These people are forceful, commanding, and demanding. They know how to handle adversity well and can deal with any hand they’ve been dealt. They are exceptionally resilient and resourceful. This probably arises out of their keen awareness that nothing lasts forever.
So, which do I use?
If you’re new to astrology, you’ve likely felt overwhelmed by so many options. Deciding which system to use is hard, and developing our own rationale when we have no experience of our own can lead to heedlessly believing anyone who practices astrology if they seem authoritative enough. I believe that there’s a huge value in experimentation and allowing ourselves to make decisions even if we’re not 100% sure of them because the information we’ll have learned after that choice will be priceless.
With that being said, here’s a table of pros and cons I’ve devised for each model.
Chaldean Decans
Pros
Historical and empirical model with centuries of data and use.
Consistency in interpretation and delineation.
Cons
No integration of the 3 outer planets in our solar system.
No innovation, stagnancy.
Modern Decans
Pros
Innovative approach to astrology.
Additional nuance by integrating the 3 outer planets.
Cons
Volatile or inconsistent results in comparison to the tradition.
Dubious rationale for this system and insufficient empirical data.
With time and practice, astrological synthesis paired with consistent studying will do wonders for one’s astrological practice. Our practice is always changing, as are our opinions, but hopefully, this article left you a little more informed and sure about which choice you’d like to make. Merry journey through the planetary spheres!
About the Author
Loaiza Pérez Heredia: A Leo rising with a 9th house stellium passionate about traditional astrology, writing, photography, history, traveling, and so much more. With two years under my belt, I'm excited about research in this field and bringing ancient astrology back to life.
Instagram: @ academicaries
Twitter: @ academicaries
References
BBC. (2021, November 24). Albert Einstein’s Hideaway in Hut Documented in New Book. BBC News. https://www.bbc.com/news/uk-england-norfolk-59401006
Brennan, C. (Host). (2014, August 21). Austin Coppock on the Astrology of the Decans. In The Astrology Podcast. https://theastrologypodcast.com/transcripts/ep-20-transcript-austin-coppock-astrology-of-the-decans/
Bryan, M. A. (2023). Mastering Traditional Astrology. Oraculos Press.
Coppock, A. (2014). 36 Faces: The History, Astrology and Magic of the Decans. Three Hands Press.
Kaku, M. (2024, March 10). Albert Einstein. Encyclopædia Britannica. https://www.britannica.com/biography/Albert-Einstein
Maternus, F. The Anthology, Chapter II.4, lines 1-2.
Rouzé, M. (2024, March 9). J. Robert Oppenheimer. Encyclopædia Britannica. https://www.britannica.com/biography/J-Robert-Oppenheimer
Temperton, J. (2023, July 21). “Now I am become death, the destroyer of worlds.” The story of Oppenheimer’s infamous quote. Wired. https://www.wired.com/story/manhattan-project-robert-oppenheimer/
Well researched. Great read!
Lovely read, full of perspective!! :)