ben heuu , c'est Orion qui le calcul
on en parle ici https://www.astro-ciel.com/t4400p25-l-astrologie-medievale
If the Sun is in the 7th, 8th or 9th in a masculine sign, then it is the Hyleg.
If the Sun is not the Hyleg, then move to the Moon.
The Moon as Hyleg
If the Moon is in ANY angular house or a succedent house and in a feminine sign and
ANY of the four rulers of her degree (Rulership, Exaltation, Triplicity and Term
aspect her then she is the Hyleg.
Degree of Ascendant as Hyleg - Conjunctional
If the Sun and the Moon cannot be Hyleg and the chart is Conjunctional, then take the
degree of the Ascendant. And if any of the above rulers of the Ascendant aspect the
Ascendant, it will be the Hyleg. If the Ascendant is not the Hyleg, then use the Part of
Part Fortune as Hyleg - Preventional
If the Sun and the Moon cannot be the Hyleg and the chart is Preventional, then take
the Part of Fortune
. And if any of the above rulers aspect the Part of Fortune, it will
be the Hyleg. If the Part of Fortune is not the Hyleg, then use the Ascendant.
Use the Degree of the Prevention or Conjunction as Hyleg
If all of the above fail, then look to see if any of the four rulers of the Conjunction
aspect the degree of the Conjunction. For Conjunctional charts only. (Bonatti does
not add to look to the degree of the Prevention in the same way for Preventional
If the Hyleg is still not found, then the Hyleg is said to be frustrated and the life of the
native will be short. In other words, it is a 3rd Differentia chart.
Finding the Alcoccoden
The Alcoccoden is the planet that forms a Ptolemaic aspect to the Hyleg and has the
greatest dignity in the Hyleg’s place. Thus one looks to the planets that are forming
aspects to the Hyleg. If more than one planet aspects the Hyleg and has dignity there,
then it is the planet that scores the most points. For example, the ruler would score 5
points but if another planet which aspects the Hyleg was also exalted in the place of the Hyleg and ruled the term of the degree of the Hyleg, then it would score 7 points
and would be considered the Alcoccoden.