Roger of Hereford and the First Astrology Book

by Chris Mitchell

Ask a traditional astrologer to name an early English astrology textbook, and there's a good chance they'll say "William Lilly's Christian Astrology", published in 1647. However, I would like to present, for your delight and delectation, an example that predates Lilly by almost half a millennium, and which makes the bold claim to being the first astrology text for students written in England. Ladies and gentlemen, I give you Roger of Hereford's Liber de Arte Astronomice Judicandi.

The title isn't as snappy as Christian Astrology, it must be admitted, and indeed I've taken some liberties in pretending it has a title, in the first place. In medieval times, an author would simply launch into a topic and start writing about their topic - a title wasn't really a consideration, much to the consternation of librarians centuries later. So when the hero of our piece, a teacher called Roger who worked in the cathedral school of Hereford, decided to write a textbook on astrology for his students, he started off by writing:

"Quoniam regulas artis astronomice iudicandi non nisi per diversa opera dispersa invenimus, utili astrologorum desiderio satisfacere cupientes (eis quibus ubi necesse fuerit explananationem sit) supplementionem apponentes in unum breviter colligemus".
Quoniam regulas artis astronomice iudicandi non nisi per diversa opera dispersa invenimus, utili astrologorum desiderio satisfacere cupientes (eis quibus ubi necesse fuerit explananationem sit) supplementionem apponentes in unum breviter colligemusCredit: Camb. Univ. II.1.1 fol. 46v

Which, loosely translated, means: "Since we can only find the rules of the arts of judicial astrology from a number of different texts, we shall shortly gather together in a single volume the practices of the astrologers to satisfy a frequently asked request (for those who need an explanation)". Or, even more loosely translated, "look boys, this stuff I'm teaching you is all over the place so I'm going to make life easier for you by writing the first astrology textbook in England". And so he does. It doesn't really have a title - so librarians have to either use the first sentence of the "incipit" (the opening words) of the manuscript, or make up a snappier title. Needless to say, none of them can agree on a snappy title, so I'm going with On the Art of Judicial Astrology.

We don't know a lot about Roger. We know he was active in Hereford in the late twelfth century at a time when surnames were a bit of a novelty, though he may have been called Roger Young (Rogerus Infans), and witnessed the consecration of a bishop of Hereford, suggesting he was quite high up and may have been part of the bishop's household. In common with most medieval writers, he's normally known by his first name and the place where he was active - hence Roger of Hereford. We also know, from his own writings, that he "toiled for many years" teaching in the cathedral school at Hereford. Before the rise of universities in the thirteen century, their forerunners were schools attached to cathedrals and monasteries. Although some of these schools were purely religious, some - including the one at Hereford - was secular, and taught arithmetic, geometry, music and astronomy/astrology.

It may seem surprising that astrology, given its pagan roots, would be taught in a cathedral school. However, despite the Christian church's ambivalence towards the subject, the Church did need to be able to calculate the date of Easter. The Gospels state that Jesus was crucified on the eve of Passover, a Jewish festival. The Jewish calendar is a combination of solar and lunar cycles; the month always begins with the first sighting of a crescent moon, but months always occur in particular seasons, requiring the addition of an extra month in a year from time to time to keep the months in sync with the seasons. Passover is a Jewish festival that always occurs on the fifteenth of the Jewish month of Nisan, the first month of spring. Since Jewish months are lunar, the fifteenth corresponds to a full moon. So Passover is always the first full moon after the spring equinox. Early Christians celebrated Easter on the eve of Passover, but Christians effectively celebrating a Jewish festival was considered quite contentious, so in the fourth century a more complicated rule for deciding Easter was agreed, which stands to this day: Easter Sunday is the first Sunday after the first full moon after the spring equinox. This needs to be calculated in advance, since the forty days of Lent that precede Easter need to be observed too. Being able to calculate the date of Easter many years in advance became a hot topic from the fourth century onwards, and spawned numerous controversies, and a whole new branch of science called "compotus" (later spelled more logically as "computus"), which exercised the minds of the greatest scholars. The Venerable Bede wrote a huge book on the subject in 725, which more or less settled the argument and gave a method for calculating Easter until "the end of time". Bede's method and texts continued to be copied, and the topic keenly studied in church schools, for many centuries after. Indeed, Roger of Hereford wrote a manuscript on compotus himself [footnote here: Bodl. Digby 40, fol.21v], with a few interesting innovations, in 1176. Calculating the date of Easter involves being able to understand lunar and solar cycles, as well as an understanding of the number of hours of daylight throughout the year (since one needs to calculate when it's the equinox), and this formed the basis of the applied astronomy taught in monastic and cathedral schools.

Table for calculating the date of EasterCredit: British Library Harley 3647 f2v

What is more surprising, though, is why this necessary task of understanding planetary cycles to calculate Easter should have led to the full-blown study not just of what we now think of as astronomy, but astrology too - particularly judicial astrology, using the planets to make judgements, which might sound to the church as being dangerously close to divination. I don't have a clear answer for why this was tolerated, but Roger's book was copied far and wide across England (we know of 25 copies spread as far afield as York, Norwich, Canterbury and Winchester), and was still being copied three centuries after the original, so was certainly not just an aberrant work of a lone scholar.

Certainly a prime reason why astrology was such a hot topic in the twelfth century was the sudden explosion in the availability of Arabic texts. After astrology died out - some would say purged - in the classical world after the Emperor Justinian closed down philosophical schools in 529, the study of astrology moved east and was enthusiastically pursued first by Persians and subsequently by their Muslim rulers after the rise of Islam. Baghdad, Syria and Muslim Spain became major centres of learning, and after the Muslim city of Toledo - a great centre of scholarship - was reconquered by Christians in 1085, Arabic texts on astrology became available to scholars in Christian Europe, who enthusiastically travelled to Toledo, learned Arabic, and translated them into Latin. Many of these Arabic texts were themselves translations of earlier classical texts from Greek, and so works from classical writers such as Ptolemy became known to Europeans for the first time. In addition, other Arabic texts had their own slant on astrology, and also included techniques they had discovered from Indian astrologers. Thus, by the time Roger was teaching astrology in a cathedral school, there was a whole mass of newly available texts for him to work with. His excitement at the subject is obvious from his writing, and there is some evidence that he translated works from Arabic himself and may have travelled to Toledo to do this. Having this knowledge available - and perhaps having translated some himself - he was now ready to disseminate this to a wider audience by writing his astrology textbook, and putting all the techniques into "one single volume".

So what did a twelfth century Faculty of Astrological Studies textbook actually look like?

In some senses, not that different from a contemporary textbook. It starts with a section on the difference between the tropical and sidereal zodiacs, and how to calculate houses in a chart. He gives two methods - one practical method using an astrolabe, and the other using tables in the manuscript, which he designed.

The next section talks about the nature of the signs. Some of these would be familiar to a modern astrologer, such as assigning Taurus to earth and Leo to fire. He then describes geographical areas for each sign, which come straight from Arabic texts as they relate to the Middle East (Aries is assigned to Babylon, Persia and Palestine), and types of places (Taurus for mountain caves, dry fields, pasture land and woods). Next he describes parts of the body ruled by the signs, and another technique where different parts are assigned to a sign according to which planet is in the sign; for example, Taurus rules the neck and throat, but Saturn in Taurus is associated with the stomach, Jupiter in Taurus with the back, and so on for other planets - this technique is identical to one described by the Arabic writer al-Qabisi (Alcabitius). Physical characteristics for a person identified by this sign are also given - Scorpio has an attractive appearance with much hair, small eyes and face, long legs and big feet!

The seven planets are then described, with some associations recognisable to a modern astrologer: Jupiter is handsome, warm, sweet and temperate and associated with laws, temples and festivals, and is sometimes ill-advised, and has characteristics of generosity, eloquence, grandeur and indulgence. As with signs, there are lots of physical descriptions too - a Jupiter man has a round beard, a beautiful voice, long and beautiful hair and his two upper teeth are large and separated.

Next come some standard medieval Arabic techniques - years associated with planets for a technique to calculate the length of life, and for the Arabic technique of "firdaria" to delineate sections of a person's life; the houses and their meanings; planetary strengths; aspects; tables of Arabic parts; dignities and planetary joys.

Having dealt with the basics, Roger now gets to the meat of the topic - judicial astrology itself and its techniques. It goes into detail about how to select a planet to act as "significator" for a particular horary question or election. After giving a number of rules for determining the significator and establishing its condition - whether it's in good shape or not - Roger goes on to talk about the purpose and intention of the questioner. This seems to be a very subtle idea, where it is up to the astrologer to divine the intention of the questioner, using various techniques. One of these uses "duodenaria" where a sign is divided into twelve equal parts of 2.5 degrees each, where each sign contains its own mini zodiac. For example, the first 2.5 degrees of Gemini has the nature of Gemini, the next 2.5 degrees of Gemini has a Cancer flavour and so on. This is a technique described by al-Qabisi, and Roger not only describes how to calculate which duodenarium a planet is in, but how to use it. Roger gives us a concrete example: look at the duodenarium of the significator; this will be a particular sign (so for instance, if Mars is the significator and it's at 4 Taurus, we know the first 2.5 degrees of Taurus has a duodenarium of Taurus, the next 2.5 degrees has Gemini and so on, so the duodenarium for the significator is Gemini). Roger says "if the sign of the duodenarium were to occupy the fifth house, which is the house of sons, and the lord of the fifth house were to fall in the fourth house, which is the house of heirs, one would consider the inheritance of sons". I'm not entirely sure how to read this, but I suspect it might mean that your client has asked you if his father is going to recover from his illness, but what he really means is "will I inherit dad's money soon?".

Another truly bizarre section talks about the nature of "a hidden object". This technique involves you calculating the planetary hour (presumably for when the question is asked) to be given an intriguing formula such as this one: "if in the last part of the hour of Saturn, it concerns his illness or his friends' illness, or war, or discord, or other grief. The hidden thing is the head of a bat or a bird of two colours". I puzzled for many months about why a client would ask a question about a hidden bat's head, even in the strange world that was the twelfth century, until at the Astrological Association conference I had the pleasure of catching up with Dr. Ben Dykes again. Ben explained that there is a long tradition of "provers", used right up until the time of William Lilly, where the astrologer starts a consultation by telling the client something about themselves that the astrologer couldn't possibly know, to prove the astrologer was competent - such as telling the client they had a mole on their left buttock. This would leave the client in no doubt that the astrologer had sufficient powers to answer their actual question. Ben had in fact translated a text by the twelfth-century writer Hermann of Carinthia, The Search of the Heart, on this exact topic, which he very kindly sent me, and which certainly answered my puzzlement.1

We can see, then, that Roger of Hereford wrote an extensive textbook that was apparently for the purposes of teaching boys in a monastic school about astrology. Since the concept that everything in the universe was part of a "Great Chain of Being", with God at the top, going down through angels, stars, planets, humans, animals, plants, stones and minerals, the idea that astrology could be used to understand God's purpose for humanity wasn't that controversial, and could fit in quite comfortably in a cathedral school. However, the fact that a cathedral school teacher would be teaching his students not just God's plan for us, but something dangerously close to magic and divination does raise eyebrows. For me, the big unanswered question is this: was Roger of Hereford, the author of England's first astrology book, a radical iconoclast, or was he typical of teachers in monastic schools eight hundred years ago?

1) Hermann of Carinthia trans. Ben Dykes, The Search of the Heart, Cazimi Press 2011