In episode 205 astrologers Chris Brennan and Leisa Schaim present a lecture on the ancient method of identifying the overall ruler of a birth chart, called the Master of the Nativity.
While in modern times astrologers tend to refer to the ruler of the Ascendant as the ruler of the chart, in ancient Greco-Roman astrology the method for determining the ruler of the chart was much more complex.
There are references to the master of the nativity in many of the surviving astrological texts from the Hellenistic astrology tradition, although there are not many surviving discussions about how to calculate it.
The approach that we present in this lecture is derived from chapter 30 of Porphyry’s Introduction to the Tetrabiblos, which is itself derived from a lost work of definitions by Antiochus of Athens.
During the course of the lecture we talk about how to calculate the predominator (epikratētōr), the master of the nativity (oikodespotēs geneseōs), the co-master or joint master of the nativity (sunoikodespotēs), and the lord of the nativity (kurios).
We also discuss various questions such as the arguments for and against having one overall chart ruler, the use of the master of the nativity to identify the guardian spirit or daimōn by ancient astrologers and philosophers, and the use of this doctrine to identify more important placements in a chart.
This lecture was originally presented by Chris at the Northwest Astrological Conference in May of 2017, and then again at the United Astrology Conference in May of 2018. We decided to re-record the lecture for the podcast now in order to give a more careful and deliberate presentation of the material, a better recording, and in order to open up this research to a wider audience.
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This episode is available in both audio and video versions below.
First I will outline the calculations for the different rulers of the nativity presented in this lecture, and then you will find the recordings available at the bottom of the page.
How to Calculate the Rulers of the Birth Chart According to Porphyry
Here are the rules for calculating the different rulers of the birth chart that we review in this podcast, based on chapter 30 of Porphyry’s Introduction.
The Rulers of the Nativity
There are four different rulers of the nativity that are important to pay attention to:

* Predominator (epikratētōr)
* Master of the Nativity (oikodespotēs)
* Co-Master or Joint Master of the Nativity (sunoikodespotēs)
* Lord of the Nativity (kurios)

Predominator
In order to find the Master of the Nativity you must first find the Predominator, since the Predominator is the one who designates the Master. The Predominator is typically one of the luminaries, as long as they are well-placed. If they are not, then it defaults to the Ascendant.
Here are Porphyry’s considerations for determining if one of the luminaries can become Predominator:

* The luminary that belongs to the sect of the chart is preferred (Sun day day, Moon by night).
* The luminary that is more angular is preferred over one that is in a less angular house.
* The one that is more eastern in the chart (towards the rising sign) is preferred.

* g. if the Sun is in the 1st house in a day chart, Sun is the Predominator.
* Sun in the 9th with the Moon in the 1st,

The Master of the Nativity: Finding the Ruler of the Chart

The Astrology Podcast