Dodekatemoria in Alfonso d’Este Anonymous horoscope



Several years ago I commented some techniques employed by an unknown astrologer in a judgement written for Alfonso d’Este, the illegitimate son of the Duke of Ferrara. This judgement contains many  tables summarizing several traditional techniques: of some I have already talked here.

Someone asked  me about the table concerning dodekatemoria.

Dodekatemoria are subdivisions of the twelve signs of the Zodiac into a further twelve or thirteen parts each.

In the case of 12 sub-parts we have the following:


The problem with this method is that Taurus should start with sub-Taurus so we jump from Aries/Pisces to Taurus/Taurus skipping Aries.

So while some authors choose to divide by 12, others used a different kind of dodekatemoria, which is obtained dividing the sign by 13. In this case we can go from Aries/Aries to Taurus/Taurus without forgetting the poor Aries.

This is the method as explained in Paulus of Alexandria (p.40 Greenbaum translation) :


This is again the original birth chart of Signor Don Alfonso:



This is the dodekatemoria table given by the Anonymous astrologer:


The method is easy:

Multiply the longitude of a planet by 13 and count the result from the beginning of the sign occupied by the planet.

For example let’s try with Mars, which is at 2°16′ Sagittarius.


2.26666666 x 13= 29.46666666

240+ 29.46666666 = 269.46666666

269.46666666 —– > 269° 28′  ——>  29° 28′ Sagittarius

We can do the same more quickly with Solar Fire.

We can choose Harmonic/transform and select 13.


And voila the result:


So stay home and play with Renaissance dodekatemoria !







8 thoughts on “Dodekatemoria in Alfonso d’Este Anonymous horoscope

  1. Margherita-Thank You for explaining dodekatemoria.I don’t have solar fire but Janus 5 and Morinus does twelfths.After I created the chart for Alfonso Mars was just past first twelfth at 2 41 SAG.It looks like after 2 30 degrees (x12 =30) planet goes to next sign.So he is in beggining of Capricorn. Regards-Harold

  2. Dodekatemoria could be calculated dividing by 12 or 13. This astrologer is using the second method, which is Paul Alexandrinus’ method.
    Other Hellenistic astrologers divide by twelve. For example Morinus software uses this method. On the other hand SF could divide by 12 or 13, as you prefer.

  3. Margherita-I see you use decimals for calculations-Do you know about Casio fx-260 solar calculator? Harold

  4. Margherita -This calculator converts degrees easily-All you do is press one button-Harold

  5. Margherita-Robert Zoller told me about this calculator after having a private lesson.Before this I had to press about 10 buttons to get DMS.I hope you find it useful-Harold

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