historical, astronomical, and astrological notes

by Juan Antonio Revilla

Date: Wed, 26 Mar 2003 05:25:16 -0600
Subject: [act] the horoscope of Baghdad, details

Baghdad's location, founding date and hour, and round architectural design was made according to astrological/astronomical principles. Al-Mansur brought together for this purpose...

<<... a large team of astronomers, astrologers, and engineers from places as disparate as India and Greece as well as local experts...>> []

<<In fact the site and the time was chosen by advice from Iranian court astrologer Nawbakht with help from Fazari and Tabari. These astrologers recommended 30th of July 762 as a blessed time to lay the foundation for Baghdad. Mansur accepted the verdict...>>

The original horoscope of the days of al-Mansur appears in a manuscript of Al-Biruni centuries later, "Al-Athar al-Baqiyah'an al-Qorun al-Khaliya" (The Chronology of Ancient Nations). A photograph of the manuscript can be seen in Ibrahim Allawi, "Some Evolutionary and Cosmological Aspects to Early Islamic Town Planning", published in 1988 and found at:

Ibrahim Allawi gives many documentary details and makes a reconstruction of the original horoscope. The following is based on him:

The Biruni manuscript contains copyist errors in the planetary positions, but the original data can be reconstructed thanks to the publication in 1977 in Baghdad of "Baghdad Madinat al-Salam", written by Ibn al-Faqih al-Hamadhani, a classical author who flourished around A.D. 900.

Biruni's and Faqih's planetary positions coincide roughly, but Biruni gives "July 23" as the date of the horoscope, while the correct date is given by al-Faqih: July 31st or 4 Jamadi Awwal. The Ascendant of the horoscope is 6 Saggitarius, and Allawi reconstructs the hour to "13:57 Baghdad time" using parameters from Arab authors of that time. In a modern computation, assuming true or apparent solar time, this would give an Ascendant in 0 Sagittarius.



Date: Wed, 26 Mar 2003 07:46:49 -0600
Subject: Re: [act] [Centaurs] the horoscope of Baghdad, details

The positions of the Sun, Jupiter, Venus, and Mercury given by al-Faqih, when compared with a modern computation, are in error by 2,48' - 2,48' - 2,58' - 2,53', as mentioned by Allawi. What he doesn't mention is that this displacement shows that the positions given by al-Faqih (in the case of these 4 planets) are sidereal, and correspond to the "Sassanian" zero point in 564 AD of the Toledan and Khwarizmian tables. This is also the canon used by Masha'allah, a contemporary of Nawbakht and the court of al-Mansur, so the Persian "Tables of the Shah" were used for the calculation of these 4 planets in the horoscope of Baghdad.

[about the Sassanian zero point, see Mercier, p. 207-208. The Mercier reference is found in the Swiss Ephemeris documentation. Both Swewin32 and Riyal can calculate sidereal positions with this Sassanian zero point]

Allawi's reconstruction is historical, aimed at reproducing the original horoscope. To re-calculate the horoscope with modern standards, one has to follow a different procedure in order to find the time for which it must be calculated.

We know that the Ascendant is 6 Saggitarius. We also know the position of the Moon:

according to al-Biruni = 29,10 Libra (probably a copyist error)
according to al-Faqih = the Moon is not mentioned
[ref. Allawi p.65]

If instead of 13:57 we use 14:25 local apparent time (2:28 p.m. LMT), we obtain:

Ascendant = 6,11 Saggitarius
Moon = 27,33 Libra.

According to Allawi, the 6 Sagittarius (246) Ascendant was chosen to coincide with the terrestrial longitude of Baghdad. Longitudes were measured from the mythical city of Kandakas in Eastern China, and Baghdad's longitude is listed at that time as 7h36m, i.e., 144 degrees from Kandakas, or 246 from the vernal equinox.

The data for the horoscope in modern terms should then be:
July 31, 762
2:28 LMT, Baghdad



Friday, 11 April 2003, at 6:55 a.m.,
Subject: Re: The Founding of Baghdad Horoscope

... the July 31st date is not based simply on the horoscope given by Biruni 2 centuries later, but on 3 independent sources that corroborate one another: "Biruni, Ibn-al-Faqih, and Tanukhi's summary of the Kitab-al-'Uluf of Abu Ma'shar" (p.62, fig.4 of Allawi).

Ibn-al-Faqih, as I explained, was an Arab author of ca. A.D. 900, and according to Allawi he not only gives the specific date, but the planetary positions he quotes agree with those of Biruni and with the scant notes available from Abu-Ma'shar.

After studying the original documents in Arabic and giving the references, Allawi specifically mentions (p.65) that "there are several versions of the founding date... [but they are] wrong, though they probably are important in that they reflect previous attempts to found the city which were abandoned because they were inauspicious".


NOTE: As a confirmation of this, I would like to add the following comment by the historian David Pingree:

"The next phase in the history of Arabic astronomical texts is marked by a further infusion of Indian material accompanied by translations of the Ptolemaic 'Syntaxis' and 'Handy Tables' and of the Iranian 'Zij al Shâh'; this activity took plave at the early 'Abbâsid court, and particularly under al-Mansûr and Hârùn al-Rashid. When the former was planning to build his new capital, Baghdâd, he assembled the astrologers Nawbakht, Màshá-allâh, al-Fazâri, and 'Umar ibn al-Farrukhàn al-Tabari to determine an auspicious moment; they chose 30 July 762." [ ref.: David Pingree, The Greek influence in early Islamic mathematical astronomy, Journal of the American Oriental Society, 93: 32-43, 1973 ].


Date: Fri, 28 Mar 2003 09:47:49 -0600
Subject: [act] the horoscope of Baghdad, more details

One can read online an extract of William Holden's "A History of Horoscopic Astrology" (Tempe, Az., American Federation of Astrologers, 1996, pp. 99-129) at the C.U.R.A. site:

where this horoscope is mentioned together with its correct date and time ("about 2 p.m."). The source is given as Biruni's "Chronology of the Ancient Nations", p.263 of the Sachau edition.  However, we must remember that according to Allawi, Biruni gives the date as "July 23".

Also in that site you will find a note written recently by Holden: "The Foundation Chart of Baghdad". The reference to al-Biruni is given again, though this time he settles for a time of "2:40 p.m. LMT".  He says that <<no cuspal degrees are given, but we can assume that the astrologers chose the time when Jupiter was in the ASC degree. This would have been at about 2:40 PM LMT>>. He also mentions what was missed by Allawi, that <<the astrologers used a fixed zodiac that differed by about 4 degrees from the tropical zodiac.>>.  [ref. ].

No other detail of the copy of the horoscope found in Biruni is given. Apparently the "2:40 p.m." was chosen by Holden to put the Asc. of the chart in 6 Sag according to the 4 degrees displacement he mentions, but he gives no clue as to how he found this displacement or what secondary literature he used as source.

Recall that Biruni's data contains copyist errors and is incomplete, and that the horoscope does indeed has a 6 Sagittarius Ascendant according to Allawi, who asserts that the original horoscope date and time can be reconstructed <<from data reported by Biruni, Ibn-al-Faqih, and Tanukhi's summary of the Kitab-al-'Uluf of Abu Ma'shar>> (p.62, fig.4).

We have seen that this "4 degrees"  Holden mentions is the starting point of the Sassanian ayanamsa that was the basis of the "Tables of the Shah" used by Masha'Allah, and presumably also Nawbakht.

Michael Rideout was wondering why one would use sidereal positions for the planets and tropical for the Ascendant, as I did. I don't think this is uncommon in medieval astrology, but let's assume, as Holden is doing, that everything was done according to one single astronomical canon. In the following comparison, I use Riyal with the Sassanian ayanamsa (zero point of 564 AD) and the data provided by Ibrahim Allawi. Calculations are done for 2:41 p.m. LMT of Baghdad (GMT 11:43:24):

Sun = 8,02 Leo (Biruni=8,10, Ibn Faqih=8,10)

Mercury = 24,09 Cancer (Biruni=25,07, Ibn Faqih=24). -- NOTE: this is assuming an error of Allawi, who gives the position as "Gemini" instead of Cancer as Michael pointed out)

Venus = 29,59 Gemini (Biruni=29,08, Ibn Faqih=30)

Mars = 4,10 Gemini (Biruni 2,50, Ibn Faqih 2,04)

Jupiter = 6,02 Sagittarius (Biruni=n.d. -- no data, Ibn Faqih 6,00)

Saturn = 28,41 Aries (Biruni=1,40 Aries, Ibn Faqih=1,25 Aries). -- NOTE: this discrepancy is incomprehensible to me. It may be another error of Allawi, since he uses Tuckerman's tables and finds an error of only 0,15'... ???

Moon = 24,55 Libra (Biruni=29,10, Ibn Faqih=n.d.)

Mean Lunar Node = 25,20 Capricorn (Biruni=25,00, Ibn Faqih=n.d.

Ascendant = 6,09 Sagittarius.

As you can see, with the exception of the Moon, the anomalous Saturn, and the 1 degree error (Biruni) or 2 degrees (Ibn Faqih) of Mars, all the other positions agree closely, so it is reasonable to use --like Holden-- the 2:41 p.m. time (sidereal Ascendant, corresponding to 8 or 9 Sag tropical) instead of 2:30 (tropical Ascendant).

Anyway, there are several possibilities, and things unsolved about this horoscope.

One more point of interest: It would be good to know if medieval astrologers were aware of these deviations of sidereal from tropical positions when they were using the tables. According to Raymond Mercier (reference given part I, p.205):

<<Of course, these calculations which we have made to find the deviation at the true equinox, were not available to Medieval astronomers, and there is no way in which they might have inferred from the internal structure of these solar tables that they were correct in A.D. 563. It is also unreasonable to suppose that the date of the equinox  for that year was known with sufficient accuracy to enable the solar tables to have been adjusted then, or at a later time, so that they were without error in A.D. 563. In any case, it is not clear in what way medieval users were concerned to interpret what we have called the deviation.>>



Date: Fri, 28 Mar 2003 19:41:38 -0600
Subject: Re: [act] [Centaurs] the horoscope of Baghdad, more details

"Saturn = 28,41 Aries (Biruni=1,40 Aries, Ibn Faqih=1,25 Aries). -- NOTE: this discrepancy is incomprehensible to me. It may be another error of Allawi, since he uses Tuckerman's tables and finds an error of only 0,15'... ???"

The answer seems to be that, in this case, Allawi made the same mistake he made in the case of Mercury, since the tropical position of Saturn at the time was 1,26 Taurus, which explains why he found an error of 0,15 comparing Tuckerman's position with Biruni's. Since he gives the "Aries" position as coming both from Biruni and from Ibn Faqih, one wonders how did he come to that wrong assumption from the original material.

Any clue or bibliographical reference is appreciated.



Date: Wed, 16 Apr 2003 10:10:39 -0600
Subject: Re: [act] Repost of the Baghdad post by M Rideout

Mercier's  article "Studies in the medieval concept of precession" is quite large (65 pages) and complex. I will try to summarize what is relevant and more interesting to this discussion, in an effort to understand it myself.

The analysis begins with the Toledan Tables (11th Century). Mercier points out that these tables are based on the sidereal year, unlike the tables of Ptolemy. The use of the sidereal year had its antecedents in the Kwarizmian tables (9th Century) and the Babylonian methods of the Indian astrological/astronomical tradition.

Since the longitude of the Sun in the Toledan tables is calculated sidereally, then it follows that its position will correspond to the tropical position of the Sun with respect to the equinox of one specific date, and of only that date. In all the tables in the Indian tradition to which the Toledan Tables apparently belong, this date is found somewhere between A.D. 450-650. The zero point of this tradition agrees with the end point of the lunar mansion called Batn al-hut in Arabic, Revati in Sanskrit, and K'uei in Chinese, determined by the junction stars: beta Andromedae, zeta Piscium, and eta Andromedae.

There is a record of one Guillaume de St Cloud, a leading figure in Astronomy by the end of the 13th Century, who proceeded to calculate the motion of the 8th sphere in order to compare astronomical tables known at his time. For this, he observed the exact time of the Spring equinox in the year 1290, and deduced that the 8th sphere had moved 10;13. There is no record of how he did all this. The time of the equinox he observed according to Mercier was 16h after noon of Sunday 12th, March 1290 (julian date 2192301.6 "ignoring the correction due to the difference in longitude between Greenwich and Paris").

Mercier proceeds to calculate the true longitude of the Sun at that date according to the Toledan Tables, and he obtains 19,47'59" Pisces, i.e., 10,12'01" from the true tropical position obtained by Guillaume. This "ayanamsa" (Mercier does not use this term), compared to Guillaume's figure of 10,13' shows that he was calculating his result using the Toledan Tables.

Using Tuckerman's tables, Mercier calculates the correct time of the equinox in 1290 as 17h50m after noon of 12th March. This would make the ayanamsa 10,09'. Rough calculation shows that the zero point of the Toledan Tables in somewhere in the 6th century. Mercier tries to make a more precise calculation by comparing the mean motion of the Sun according to the Toledan Tables (sidereal) and the modern tropical mean motion, obtaining a difference of 50.616" per year, and this allows him to put the zero point in A.D. 563/564.

Then he examines the Tables of al-Kwarizm, also based on the sidereal year. He calculates the "movement of the 8th sphere" according to the tables using the same procedure (i.e., calculating the deviation from zero of the true longitude of the Sun according to the tables at the times of the Spring equinox). He obtains the following:

A.D.      Kwarizmian      Toledan
560       -0,02'10"      -0,02'41"
561       -0,01'15"      -0,01'54"
562       -0,00'21"      -0,01'07"
563        0,00'33"      -0,00'19"
564        0,01'27"       0,00'28"

Mercier shows that this zero point is only 0,10' East of zeta Piscium, and notes that although this star was not necessarily the origin of longitudes in these tables, it was indeed used as such in the Indian tradition of the Surya Siddhanta, written around A.D. 600. He reasons (p.206) that "the authors of both the Kwarismian and Toledan tables must have had the date 562/3 explicitly in mind, for in no other way could it have been arranged that the two solar Tables [--which differ in everyone of the 4 solar parameters--] could agree."

The question is how did they arrive at that date?

He mentions a study made by Billard of the Indian material, where the result represents "not the exact date at which any particular deviation vanishes, but rather the date at which the sum of squares of selected deviations is minimum". In the case of the Brahmasphutasiddhanta (A.D.628), Billiard concludes that A.D. 562.8 "might be regarded as the date which represents overall the origin of the sidereal coordinates". This tends to confirm what has been suggested by several scholars that the Kwarizmian Tables descend in part from the Brahmasphutasiddhanta, if one assumes that this is the system known to the Arabs as the Sindhind.

But Mercier shows that an exact calculation using the Brahmasphutasiddhanta would put the zero point in A.D. 580, making it clear that the position of the Sun in the Kwarizmian Tables is not derived from it. Another explanation must be sought for the A.D.562/3 date, and this explanation is found in the Sassanian Zij al-Shah, known as the Tables of the Shah, associated with the reforms of Khusrau Anushirwan (reigned 431-579). A close examination of an account by al-Biruni in his "India" (Qanun'l-Mas'udi) of the reform of the Zij al-Shahriyaran in A.D. 556 ordered by Khusrau permits to reconstruct the rationale of this date, and the key is the role played by the planet Jupiter.

The passage of Biruni refers to the doctrine of the "Thousands":

<<In their opinion the seven planets and the two nodes follow one another with a constant number of years for each; we call this number fardariyat. They agree that in the 25th year of Anushirvan, 4 years of the Fardariyat of Jupiter had elapsed, and there remained 8. Then the fardariyat of Mercury, 13 years; then Saturn, 11; then the Tail, 2; then Mars, 7; Venus, 8 and the Sun for 10 and the Moon 9 and the Head 3, the again Jupiter around the Zodiac in relation to its exaltations, during the space of 75 years.
<<We mentioned the above date (25th year of Anushirvan) because at that time the astronomers of Persia met to correct the Zij al Shahriyaran known as al-Shah, and they recorded  the measures of times and stations. They knew from the position of Jupiter at the end of the month Aban  that 3 hazar had passed and of the 4th, 851 years. This if we discard 75-year cycles 51 times, there remain 26 years, which begins with the fardariyat of the Sun and ends with the first 4 years of the fardariyat of Jupiter. From this point to the beginning of the reign of Yazdagird there are 76 years: 23 of Anishirwan, 12 of Hormuz, 37 of Parviz, 4 of Shiruya. Thus at the beginning of the reign of Yazagird 5 years had elapsed of the fardariyat of Jupiter.>>

Mercier notes:

- 25th year of Anushirwan = A.D. 556
- the fardariyat of Jupiter ran from 552 to 564.4
- of all these fardariyat, only that of Jupiter has any astronomical significance, since we have then the sidereal period.
- end of Aban = early March
- 3851 = 51 x 75 + 26
- Khusrau Anushirwan = 531-579; Hormuz IV = 579; Khusrau Parviz = 591-628; Shiruya (and others) = 628-632; Yezdagird = 632-651

I quote Mercier now:

<<When the planet was observed in Aban 556 it was visible during much of the night, but at the termini of the fardariyat, in 552 and 564, it was in conjunction with the Sun almost exactly at the moment of the Spring Equinox. Nowhere else in the sequence of fardariyat of Jupiter or the other "stars" is there any clear astronomical phenomenon at the termini.>> (page 208)

<<The outstanding astronomical event at that time is the conjunction of Jupiter with the Sun at the time of the Spring Equinox of 564, and I had already argued that the event was crucial in fixing the parameters of the [Kwarizmian] Tables. This conjecture is now fully justified by the passage in the Qanun'l-Mas'udi, where we saw that observations of Jupiter were carried out under Khusrau Anushirwan in 556 by way of fixing a cycle of Jupiter for the interval 552-564...

<<Observations of Jupiter play a major role in ancient and medieval calendars, and seem to have served to link observations of the day and night sky, so important obviously in the phenomenon of precession...

<<Kugler in his study of Babylonian tablets of Jupiter's motion found that the planet was used as a "calibration marker" in a sense, regulating the lunar calendar in Babylonian astronomy...>>
(page, 43 of part II)

There are many other details (references and ancient primary sources) that Mercier gives to strengthen his explanation based on the role of Jupiter, but I don't have the time to put them all. They all refer to the same idea



Date: Wed, 26 Mar 2003 17:25:59 -0600
Subject: [Centaurs] the horoscope of Baghdad, 2

With the "coalition" (actually, Anglo-American) army getting closer and closer to Baghdad, one would naturally look for a focal determinator in the horoscope of the city getting closer and closer to its exact aspect or culmination. To be "at the gates of Baghdad" could be shown for example by a planet or centaur over the traditional horizon of 6 Sagittarius/Gemini...

Anyway, I work with sidereal positions:

natal Ascendant of Baghdad = 28,40 Scorpio (the equivalent of tropical 6 Sag)
natal Mars of Baghdad = 29,25 Taurus

right now:
transiting Saturn = 28,19 Taurus direct.
transiting Chariklo = 28,02 Leo Rx.
transiting Pluto = 25,09 Scorpio Rx.

Transiting Saturn is over the cusp of the house of war and open enemies (7th), about to make exact conjunction with the natal Mars. Saturn has been making this aspect since July 2002, when it crossed Mars on July 25. It then went retrograde in mid-October, crossing Mars and the Descendant backwards in early January. It went stationary direct on Feb 22, 1 degree below the Desc., a few days after the Peace rally of Feb 15th, and now is crossing the horizon and Mars again with great impetus for the last time, "finishing" what it had started in the middle of 2002. The exact, third and last conjunction with Mars happens on April 11th.

Chariklo is here showing its somber aspect, which I have suggested before (see my comments on Israel/Palestine and on Chechenia) relates to mourning and the destroyed families. But the present situation calls for a far more aggressive orbital sweeper in addition to the sober sadness of Chariklo. We already have that in the TL66/Moon opposition, however, acting behind Chariklo this time we have the object that we can equate with the apocalyptic sandstorm and death: CY118. This is the only centaur/tno object in addition to Chariklo among the nearly one hundred included in Riyal that is involved.

I mentioned CY118 in my discussion of the Peace demonstrations, and at that time I recapitulated:

Sun WTC attack = 24,05 Leo (sidereal)
CY118 WTC attack = 23,45 Leo

Moon WTC attack = 3,19 Gemini (sidereal)
CY118 G.W.Bush = 4,00 Gemini
Saturn Afghanistan = 3,50 Gemini

Moon U.S. Boyd "war" chart = 29,17 Virgo
CY118 U.S. Boyd "war" chart = 29,13 Pisces

These positions show that 1-) CY118 is a clue regarding G.W. Bush "war against terrorism",  2-) CY118 is related to mass destruction and terrorism, and 3-) CY118 is related to the breakdown of the International order or "pact" between nations that had been established after WWII. Now we can check its position with respect to the chart of Baghdad:

[natal CY118 Baghdad = 7,13 Pisces (sidereal) --not in Riyal]

-- transiting CY118 conjunct Moon of Islam:

from November 1999 to June 2001. Note that with just a little orb the last pass is linked to the WTC attack.

-- transiting CY118 square Baghdad's Ascendant/Descendant:

a-) it sits (sr) in late December 2002 in 27,57 Leo, less than 1 degree from the exact square.
b-) it is right now in exact square with Pluto in 25 Leo
c-) squares the Asc./Desc. of Baghdad in October 2003, square Mars in November
d-) it retrogrades and stations in 27,37 Leo in June 2004
c-) squares the Asc./Desc. and the Mars of Baghdad in August/September 2004.

So, obviously, CY118 is related to whatever is going to happen to Iraq after the war, for good or bad. It prepares the stage for the conjunction of Pluto with the Ascendant in 2005. Seeing the aspects with natal Mars (CY118 square, Pluto opposition) leaves me wondering...



Date: Wed, 26 Mar 2003 11:22:16 -0600
Subject: [Centaurs] the horoscope of Baghdad, 2

In a recent post (Feb 23) I had noted the very intense focality of 19 degrees of the cardinal signs (sidereal):

Sun of Islam = 19,52 Cancer
Varuna of Islam = 18,42 Cancer
Mars Kingdom of Iraq = 18,59 Cancer
Neptune Kingdom of Iraq = 20,27 Cancer

AW197 winter solstice 2002 = 19,49 Cancer
TL66 winter solstice 2002 = 19,08 Aries
Venus at winter solstice = 20,06 Libra
Mars at winter solstice = 18,22 Libra
Hylonome at winter solstice = 18,03 Libra

By February 15th, the day of the world-wide Peace rally, Hylonome was in 19, 27 Libra.

During the past days I had wanted to write something about the present Hylonome square to the Sun of Islam, since the meaning is so obvious (Hylonome = "the cry of the poor", "war song", "death song", "sacrificial victim", etc.), but I was disheartened by the role the Arab League has played in this crisis: as always, a lot of talk and nothing else. The alleged union between Arab nations is only words in the mouth of cynical politicians.

Perhaps, seeing the monumental cynicism and hypocrisy of Arab leaders today, the square could be interpreted in terms of a confrontation, as can be seen in the news: the plight of masses of people on the streets to their leaders, angrily and helplessly witnessing how the Iraqis (and before that, the Afghans), are being invaded and humiliated. This at a level that had not happened since WWII.

Anyway I had left this aside because I feel 1-) that the square is not a focal enough aspect, and 2-) that "Islam" was too general an entity and had proved to be inoperant at the political level. What I wrote above, however, may be the way to begin to understand the meaning of that Hylonome-Sun square, and will help give more consideration to the "devastation" or "Apocalyptic humour" of the square of TL66 from the other side.

But examining the chart of Baghdad, I find a very telling or eloquent testimony of the meaning of Hylonome and TL66, symmetrically and critically mediated by the Sun of Islam:

Moon horoscope of Baghdad = 20,03 Libra
Hylonome is effectively in conjunction from Feb 2003 to July 2004.
TL66 is effectively in opposition from May 2002 to January 2004.


Return to index page