Updated: Mar 30
A series that explores each 10° segment of the signs
Today we're going to begin our exploration of the decans. To begin, we're going to go over exactly what decans are, their astrological importance, and how we can use them to gain further insight for a placement, especially the Soul of a nativity. This post is going to give all the background information needed to understand the decans, then I'll be making a 36 individual posts to describe each decan in detail.
"Did she say 36 posts?" I sure did. The reason there's going to be 36 posts is because there's 36 decans! But before we get too far into this, what does decan mean?
The word decan has the prefix "dec", which is derived from Latin meaning "ten". Think of words like decade or decathlon, where the number 10 is crucial to the meaning of the word itself. The same goes for decan. Decans in astrology are 10° segments of the zodiac signs. I cast the chart for when I started writing this post and included the decans. The three equal 10° segments under each zodiac sign are the decans for that sign. The decans are broken into the following sets of degrees: the first is 0°-9°, the second is 10°-19°, and the third is 20°-29°.
Since most of my astrological practice is rooted in traditional techniques and teachings, the decans I use are called the "Chaldean" decans. The word Chaldean is referring to the Chaldean Order, which is when we put the planets in order of planetary speed. The Chaldean Order follows as such: Moon - Mercury - Venus - Sun - Mars - Jupiter - Saturn. The decans as they're arranged around the zodiac are in descending Chaldean Order, meaning they go from slowest orbit to fastest orbit, beginning with Mars in Aries. The rational for beginning with Mars comes from the fact that Aries' domicile is Mars. From there the decans move in descending order and continue around the zodiac until each 10° segment is assigned a planet.
I wanted to make a note that modern astrologers tend to use decans based off the order of triplicity lord of the sign. Aries being a Fire sign means that Mars would the ruler of the first decan, the Sun would be the second decan due to Leo, and Jupiter would be the third decan due to Sagittarius. Let's do another example just for the sake of clarity. Libra's first decan would be Venus, the second would be Saturn because of Aquarius, and the third would be Mercury due to Gemini. I can't speak much to the meanings of these decans or their information, as I don't use them. But I wanted to make sure I go over them in case you see other decans designations. Neither system is "the correct" system. I simply teach the traditional technique because that's what speaks to me and has worked well within my practice.
The decans themselves were originally derived from 36 stars/star groups that the ancient Egyptians used. These 36 stars became associated with various Gods and Goddess, and thus the decans were thought to have immense magic and power. As time marched forward the use of the decans melded with Hellenistic astrology and the 36 decans were placed over the 12 signs of the zodiac; each sign having their own 10° portion, as well as its own God/Goddess and mythical depiction. As we get into interpreting the decans we'll see that these depictions are extremely important and give much insight to the power that each decan holds. Decans definitely have a magical bent to them and are an essential tool in astro-magic. There's even decan associations with tarot cards thanks to the Golden Dawn and Aleister Crowley.
Now that we know what a decan is and how they're assigned, let's discuss what we can glean from them.