In Hellenistic astrology

Hellenistic astrology

Hellenistic astrology is a tradition of horoscopic astrology that was developed and practiced in Hellenistic Egypt and the Mediterranean, whose texts were written in Greek , mainly around the late 2nd or early 1st century B.C.E...

, the hyleg is the Persian

Persian language

Persian is an Iranian language within the Indo-Iranian branch of the Indo-European languages. It is primarily spoken in Iran, Afghanistan, Tajikistan and countries which historically came under Persian influence...

-Arabic term for the planet with the greatest essential dignity

Essential dignity

In astrology, essential dignity is the strength of a planet or point's zodiac position, judged only by its position by sign and degree, or its essence--what the pre-eminent 17th-century astrologer William Lilly called "the strength, fortitude or debility of the Planets [or] significators." In other...

 in five important natal chart

Natal chart

In astrology, a natal chart is a stylized map of the universe with the "native" at the center. It is calculated for the exact time and location of the native's birth for the purposes of gaining insight into the native's personality and potential...

 positions (according to Ptolemy

Ptolemy

Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

's Tetrabiblos

Tetrabiblos

The Tetrabiblos , also known under the Latin title Quadripartitum , is a text on the philosophy and practice of astrology, written in the second century AD by the Alexandrian scholar Claudius Ptolemy ....

):

• the degree of the Sun
  Sun (astrology)
  The sun is considered a very important part of astrology. It, as well as the Moon, are the most important of the astrological planets, and the two of them are often referred to as the luminaries. In Greek mythology the sun was represented by Apollo, the god of light, and Helios, the god of the sun...
  
  
• the degree of the Moon
  Moon (astrology)
  The Moon is the Earth's companion satellite. The Moon is large enough for its gravity to affect the Earth, stabilising its orbit and producing the regular ebb and flow of the tides. The Moon is also familiar to us for its different phases, waxing and waning in appearance in an unchanging cycle...
  
  
• the Ascendant
  Ascendant
  The ascendant , or rising sign, is the zodiacal sign and degree that was ascending on the eastern horizon at the specific time and location of an event. According to astrological theory, celestial phenomena reflect or determine human activity on the principle of 'as above so below'...
  
  
• the Lot of fortune
• the pre-natal syzygy
  Syzygy (astronomy)
  In astronomy, a syzygy is a straight line configuration of three celestial bodies in a gravitational system. The word is usually used in reference to the Sun, the Earth and either the Moon or a planet, where the latter is in conjunction or opposition. Solar and lunar eclipses occur at times of...
  
  (that is, New Moon
  New moon
  In astronomical terminology, the new moon is the lunar phase that occurs when the Moon, in its monthly orbital motion around Earth, lies between Earth and the Sun, and is therefore in conjunction with the Sun as seen from Earth...
  
   or Full Moon
  Full moon
  Full moon lunar phase that occurs when the Moon is on the opposite side of the Earth from the Sun. More precisely, a full moon occurs when the geocentric apparent longitudes of the Sun and Moon differ by 180 degrees; the Moon is then in opposition with the Sun.Lunar eclipses can only occur at...
  
  , whichever most closely preceded the birth.)

Some ancient authorities (viz. Vettius Valens

Vettius Valens

Vettius Valens was a 2nd-century Hellenistic astrologer, a somewhat younger contemporary of Claudius Ptolemy.Valens' major work is the Anthology, ten volumes in Greek written roughly within the period 150 to 175. The Anthology is the longest and most detailed treatise on astrology which has...

) used slightly different chart positions to obtain the hyleg.

The word "hyleg" also appears in Chamber's Dictionary (1999) with the definition stating "the ruling planet at time of birth". The word derives from the Middle Persian

Middle Persian

Middle Persian , indigenously known as "Pârsig" sometimes referred to as Pahlavi or Pehlevi, is the Middle Iranian language/ethnolect of Southwestern Iran that during Sassanid times became a prestige dialect and so came to be spoken in other regions as well. Middle Persian is classified as a...

 word "hîlâk" meaning "nativity

Natal chart

In astrology, a natal chart is a stylized map of the universe with the "native" at the center. It is calculated for the exact time and location of the native's birth for the purposes of gaining insight into the native's personality and potential...

".

Note

1. Claudius Ptolemy. Tetrabiblos. Greek
   Koine Greek
   Koine Greek is the universal dialect of the Greek language spoken throughout post-Classical antiquity , developing from the Attic dialect, with admixture of elements especially from Ionic....
   
   work from ca. 150 A.D. Various English translations. The Loeb Library translation by F.E. Robbins is available on the web http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Ptolemy/Tetrabiblos/home.html See section II, Chapter 10.