The Hellenistic Hyleg
In Hellenistic Astrology, the Part of Hyleg or simply calld “Hyleg” marked “the giver of life” position on the chart. It based on whether the person was born during the day, or at night in a hylegical area and then subtracts the last Full Moon prior to the event. It like the Part of the Fortune and other Arabian parts, is a calculated and so virtual point on the chart.
Defining Hyleg
All possible Hylegical areas are marked on our featured image in yellow. Hyleg’s are measured by the Right Ascension, which is similar to longitude — the long bands of geographic reference on the earth’s globe (see below), and are always recorded in terms of hours, minutes, and seconds with the ZERO point being the vernal equinox, approximately March 20-21 in the geographical Northern Hemisphere (above the equator) and September 1st in the Southern (below the equator).
Right Ascension is Longitude
Hylegs are measured by the Right Ascension, which is similar to longitude — the long bands of geographic reference on the earth’s globe (see below), and are always recorded in terms of hours, minutes, and seconds with the ZERO point being the vernal equinox, approximately March 20-21 in the geographical Northern Hemisphere (above the equator) and September 1st in the Southern (below the equator).
Declination is
Latitude + Geographic Coordinates
Latitude is the horizontal lines on the globe. They tell how far a place is from the equator. We see that position on our astrological charts as declination. By using the two coordinates you can find any spot on the globe. The following exercise will not work for people in apartment buildings, you need two separate house numbers.
Using this site, put in your address, write those two numbers down, and then put in your neighbor’s down the street address or next door. The two sets of numbers will be different — not remarkably but different. The set of numbers that you got is the geographic coordinate of that location. Here is an extreme example: 74.69 North 94.82 West are the coordinates for Resolute, Nunavut, Canada, while The Royal Botanic Gardens in Sydney, NSW Australia has the geographic coordinate of 33.86 South 151.22 East.
The East-West suffix tells you in which direction on the prime meridian, see the center line on the globe above, to look. East is on the right-hand side; West on the left. The North-South coordinates tell you whether to look above the Equator (north) or below (south).
Back to Hyleg
Hyleg is the Sun’s position as determined by the Right Ascension (i.e. longitude). It is typically abbreviated as R.A. The Part of Hyleg can never be the astrological Northern Hemisphere so the Second, Third, Fourth, Fifth, Sixth and Eighth Houses are all out as they are considered that the Sun is asleep. An example here is I was born at night, and my Part of Hyleg is the Third House, so it is invalid for the Hyleg calculation. Instead for night events, the term Prorogatory is used. While similar to Hyleg, it uses the
Instead for night events, the term Prorogatory is used. While the idea is similar to Hyleg, it uses the Moon’s position via the Right Ascension. Prorogatory positions do not count for this exercise, that is another essay, another time.
In the Hellenistic Chart for Ms. Winner, we see that since she was born during that day, 17:00, she has the Part of Hyleg in her First House conjunct her Part of Fortune. (Download the map to review this.) This Hylegical position was considered fortunate for the person’s health. So using this calculation, we know that Ms. Winner is a healthy young woman, and about that’s it.
Why use Hylegs?
The Hyleg position is no longer used because many find it disconcerting and akin to fortune telling to know when someone will die, particularly as the accuracy is questionable. Of course, not everyone agrees. Robert Zoller in his book on Arabian Parts in Astrology: A Lost Key to Prediction does discuss it, as does Bernadette Brady.
The reason for Hylegs was it a method of how astrologers determined a lifespan. The idea was that when the Hyleg point progresses to an Anaretic one, Anareta being the “taking of life” and the opposite of Hyleg, the native was presumed to have run the course of his natural years.
We will not be doing that progression for Ms. Winner, we are just using her chart of an example of where it is located and what Hyleg means. If you would like to do hers, or your own, be our guest. There are several methods out there, Ptolemy (born 100 AD) and Guido Bonatti (born 1296 AD) are the most common.
Footnote

From William Joseph Simmonite’s book, the Complete Arcana of Astral Philosophy or the Celestial Philosopher being Genethiology Simplified, or the Doctrine of Nativities to which is added the Ruling of the Microcosm, published by Jas. Neville, Printer, 134 Carver Street, Moorhead, Sheffield England 1890.
The reality medieval natal with a hylex depicted.