by Graham Robb
They would have been acquainted with klimata and the division of the inhabited world by Ephorus (c. 350 BC) into four zones based on the solstice angles of the sun.
Aristotle would have been known to them as a leading authority on the teachings of Pythagoras but also as the philosopher who had refined the system of klimata.
34. Division of the world by Aristotle
Aristotle, Meteorology (350 BC), II, 6, and the zodiacal path identified by Pythagoras. The twelve directions were conventionally named after the winds that blew from those quarters. The ‘Ever-Visible’ and ‘Invisible’ Circles (referring to the setting of stars) are the Arctic and Antarctic Circles.
The diagonals or solstice lines are the lines known to sailors as rhumb lines: the navigator chooses a bearing and holds to that bearing until the destination is reached. The centre of the Aristotelian earth was Rhodes, where the angle of the solstice sun in the fourth century BC happened to be exactly sixty degrees or one-sixth of a circle. (This is the angle of the solstice lines shown in the two diagrams above.) To an observer in more northerly latitudes, the angle was noticeably different, but on the geometrical evidence of the pink-granite basin and countless everyday objects of Celtic art, the Druids had the means of adapting the Aristotelian system to Celtic climes. They also had a huge, uninterrupted land mass on which to practise their navigation and to match their movements to the calculated will of the gods.
The newly qualified Druid who descended from the mountain after twenty years would know that the gods were present in every corner of the natural world, that nature itself was a temple and Middle Earth a mirror of the upper world. The temple presided over by the Druid was a material expression of those truths, a form of obedience to the immortal gods. Like the botanizing, star-gazing parish priests of later centuries, the Druid would continue to observe and record ‘the inner laws of nature’. And, as branches of the sacred oak, possessing the secrets of the earth and the sky, and knowing their motions and dimensions, thousands of Druids all over Europe would contribute to the building of another temple so vast that it would turn Middle Earth into a world in which the gods would be at home. This was the miraculous efficiency of which Eratosthenes and other lone scientists could only dream.
PART THREE
9
Paths of the Gods
With the benefit of a Druidic education, something wonderful appears on the face of Europe, something that has not been seen since the late Iron Age – a map more than two thousand years old and in an almost perfect state of repair. In its fullest form, it shows a comprehension of the earth without precedent in the ancient world. This was the heavenly vision that would help to determine the patterns of settlement and movements of population that created modern Europe.
Mediolanum Biturigum – the unlikely hub of the Gaulish wine trade, now called Châteaumeillant – was the sacred centre of Gaul in the time of the Bituriges. It stood on the longest possible meridian and on an equinoctial line running from the Atlantic to the Alps (here). A Druid versed in Greek science would have known that it had been chosen for other reasons too. Mediolanum Biturigum lies two hours due west of one of the key intersections of latitude and longitude in the Greek oikoumene: the mouth of the Borysthenes. It also lies thirty longitudinal minutes east of another key intersection – the Pillars of Hercules, where the Mediterranean meets the Atlantic. And on the line of latitude that runs one hour to the south of Mediolanum stands Delphi, the centre of the ancient world.
The system of Mediolana had been a patchy organization of local territories. Now, perhaps as early as the fourth century BC, the system was developed with such scientific rectitude that a magnificent pattern began to spread across the Continent like the roots and vessels of a great living tree. The Druids could hardly have chosen a better omphalos. Taking their bearings from the Greeks, they created a new, Celtic centre far to the west of Delphi. This siting of a prime Mediolanum is one of the earliest perceptible events in the gradual shift of power from the Aegean and the Mediterranean to the North Sea that would continue for the next two thousand years. It affirmed the place of Gaul in the wider world, and, for the first time, joined the lands of the barbarian Celts to the civilized homeland of Herakles.
35. Mediolanum Biturigum and the Greek oikoumene
The exploration of this tree begins with a simple calculation. The commonest division of klimata or lines of latitude based on the length of the longest day was thirty minutes. The line of latitude that runs exactly thirty minutes to the south of Mediolanum reaches the Atlantic near one of the ‘ends of the earth’ called Fisterra or Finisterre. But the point of intersection that lies due south of Mediolanum (marked ‘X’ on the map) seems utterly devoid of historical significance. In the foothills of the Pyrenees, in a convoluted region of limestone gullies where the medieval Cathars hid from their persecutors, the river Aude crashes through the Gorges de la Pierre-Lys. The jagged escarpment that seems to block the northern entrance is called ‘la Muraille du Diable’ (‘the Devil’s Wall’). Until the eighteenth century, when a local priest persuaded his parishioners to cut a road through the canyon, the hamlet of Belvianes was a cul-de-sac. Yet Celtiberian coins have been found there: Balbianas, as it was known in the eleventh century, was probably the estate of a Romanized Celt called Balbius. The inhabitant of this Pyrenean ‘bag-end’ lived just four kilometres from the small town of Axat beyond the southern entrance to the canyon. Axat owes its name to the Atacini tribe and was probably their tribal capital.
The former territory of the Atacini now knows little of its protohistoric past, but it could plausibly trace its history back to a certain day in 218 BC when a Carthaginian army crossed the Pyrenees, because the point marked ‘X’, half an hour of daylight south of Mediolanum, stands precisely on the Heraklean Way.
The idea presents itself like a gold coin glinting on the ridge of a freshly ploughed field. The location of the prime Mediolanum matches not only the Greek lines of latitude and longitude, but also, with even greater precision, the solstice line of the Heraklean Way. This impeccable geographical coincidence suggests a radiant invention that would otherwise appear to have existed only in the abstract form of philosophers’ diagrams – a system of klimata based not only on equinoctial lines running west to east, but also on the diagonal lines of the solstice. Logically, if the latitudinal position of Mediolanum Biturigum was determined by the Heraklean Way half an hour to the south, the route created by the mythical founder of the Celts should be mirrored by another solstice line half an hour to the north.
As though by divine decree, a line projected from Mediolanum Biturigum on the same standardized solstice bearing as the Via Heraklea (here) leads directly to the foot of the oppidum on an oval hill in Burgundy where a Celtic princess, the sister-in-love of Pyrenea, took Herakles to her bed. This was Alesia, ‘the hearth and metropolis [literally, ‘mother-city’] of all Keltika’ (fig. 37): ‘It has always been held in honour by the Celts . . . and for the entire period from the days of Herakles, this city remained free and was never sacked.’ This cosmopolitan place, whose citizens came ‘from every tribe’, is the likeliest site of the ‘locus consecratus’ where, according to Caesar, the Druids assembled ‘at a fixed time of the year’ to settle legal disputes.24 The territory was administered by a small tribe called the Mandubii (‘The People of the Horse’). As the tribe that occupied the region of the watershed and guarded the routes that joined the Mediterranean to the British Ocean, the Horse Folk enjoyed the protection of their powerful neighbours. The fabled impregnability of their oppidum was presumably a result of the tribe’s internationally recognized neutrality, and it was partly for this reason that Alesia would be chosen by Vercingetorix, leader of the Gauls, as the site of their final battle with the Romans.
From his elliptical path above Middle Earth, the sun god who had loved the princess of Alesia enjoyed a glorious view. Mirroring its southerly counterpart, the northerly line running parallel to the Heraklean Way passes through
the tribal capitals of the Agesinates, the Mandubii (Alesia) and the Lingones, through the ‘oak’ sanctuary of Derventio (Drevant), and the towns that are now Nevers and Semur-en-Auxois (another place said to have been founded by Herakles). Finally, twenty longitudinal minutes to the east of Mediolanum, the solstice line arrives with the accuracy of a Gaulish spear at the main gate of one of the most important Celtic sites in Europe.25
The Fossé des Pandours in the Vosges massif, where the route nationale snakes down towards Strasbourg, was once a vast oppidum covering a hundred and seventy hectares. It was the capital of the Mediomatrici tribe – the ‘Mothers of Middle Earth’ – and it guarded the pass now called the Col de Saverne. This is the main gateway from France to Germany and from the Lorraine plateau to the valley of the Rhine. Its Gaulish name is unknown, but, as the pass of the Mediomatrici, it may have had the same maternal connotations as the Matrona. Both passes were portals through which the sun was reborn and poured its light over the lands of the western Celts.
This northerly counterpart of the Matrona Pass, providentially positioned on the northern equivalent of the Heraklean Way, was the physical confirmation of a cherished legend: after completing his journey from the Sacred Promontory to the Alps, Herakles had wandered all over Keltika, bestowing his protection and prestige on the tribes that lived along the great rivers of northern Gaul. And this geo-political symmetry was just one feature of a celestial design that was drawn on the lands that stretched from the Alps to the Atlantic and from the ‘outermost islands’ to the Pillars of Hercules.
This mapping of a great land mass by solstice lines has a peculiarly Celtic appearance. It adopts the Aristotelian or Pythagorean system of twelve wind directions, but instead of dividing the circle of the earth into twelve equal segments, the solstice lines follow the bearing of the Via Heraklea. The original path of Herakles hugs the curve of the Mediterranean coast and heads for the rising sun of the summer solstice, following the longest possible line through Keltika from the end of the world at the Sacred Promontory. This was the baseline of the Druidic system, just as a section of its successor, the Via Domitia, was used as a baseline by the makers of the eighteenth-century Cassini map. The tangent of the real and legendary route creates a more subtle harmony than the equal divisions of the Pythagorean compass rose (here), a geometric petalling of the circle which contains a beautiful truth. Just as the arcs and tangents of Celtic art obey the coded laws of nature, the pattern of meridians, parallels and solstice lines expresses one of the fundamental secrets of the sun god.
The standardized tangent of the original Via Heraklea is identical to the tangent of its northerly sister. In modern terms, the angle is 57.53° east of north. Even in short-distance ancient measurements, accuracy to within any fraction of a degree is considered significant, and a survey tolerance of at least one degree is usually applied. The extreme precision of the Celtic lines seems at first impossible in the absence of theodolites and compasses, but to Druids versed in Pythagorean geometry, the solution would have been obvious, and it must often have been applied when they were settling boundary disputes.
Eleven steps to the east and seven steps to the north – or the same number of knots in an Egyptian rope-stretcher’s rope – make two sides of a right-angled triangle whose tangent angle is 57.53°. This whole-number ratio – 11:7 – is the simple formula that produces a Heraklean line.
Though it appeared to be a figment of legend, geography and the motion of the sun, there is something almost miraculously convenient about the path of Herakles. For a Druid mathematician, seeking correlations between the ideal world of numbers and the random arrangements of material reality, this ratio of two prime numbers, 7 and 11, would have had a particular significance.
36. The Heraklean ratio
The value of pi (π) – the ratio of a circle’s circumference to its diameter – was a Holy Grail of ancient mathematics. The elusive, irrational number required for a precise calculation of the circumference and area of a circle was one of the most mysterious and powerful utterances of the gods. The actual value of pi, to four decimal places, is 3.1416. The Egyptian Rhind Papyrus (c. sixteenth century BC) records a calculation that gives a value of 3.1605. The Babylonians and, later, the Roman army used a ratio of 25/8 (3.125) but were often content with a rough-and-ready 3. Some time before 212 BC, using regular 96-sided polygons inscribed inside and outside a circle, Archimedes proved that the value of pi lay between 223/71 and 22/7 (or 3.1408 and 3.1428). This was an impressively close approximation and a notable event in the history of mathematics.
Yet it now appears that the latter figure had been inscribed on the face of the earth more than a century before Archimedes. One of the treasures left behind by Herakles was a pathway based on pi divided by 2, the ratio of half a circle’s circumference to its diameter (11/7 equals 1.5714, which is half of 3.1428). As though by the purest chance, the Druidic system contained the closest approximation to pi in the ancient world. Herakles had supplied his Celtic sons and daughters with the geometrical secret of his solar wheel, and once that wheel had been reinvented and set in motion on the earth, there was no end to the wonders it might create.
With the formula in hand, the first obvious question is this: was a third Heraklean diagonal created half an hour of daylight to the north, in Belgic Gaul?26 Once again, when the formula is applied, a sequence of significant places appears. A solstice line projected from the point that lies half an hour due north of Châteaumeillant passes through or close by several major oppida. Most of these were probably tribal capitals before the Romans: Vannes, which owes its name to the Veneti tribe and which commanded Quiberon Bay; the city of Rennes, which became the Roman capital of the Rediones and was probably the pre-Roman capital, too, since it was there that they minted their coins; le Haut du Château near Argentan, the largest oppidum of the Arvii; Pîtres, the likely capital of the Veliocasses, surrounded by a complex of necropolises; and a ‘Camp de César’ on the banks of the river Samara, in the lands of the Viromandui or whichever tribe inhabited that part of Gaul in the fourth century BC.
Within Gaul, the coincidences are far more striking than any pattern produced by lines drawn at random. At the north-eastern end of the line, near the modern Belgian border, the coherence is less marked: the line passes within one and two thousand metres respectively of Cambrai and Famars, which were towns of the Nervii, before arriving exactly in the centre of the town of Mons, currently thought to have started life as a Roman castrum. (See the large map on this page.)
At this stage of the reconstruction, there are three Heraklean lines traversing Gaul, with a centre at Mediolanum Biturigum (Châteaumeillant) and another possible focal point at Alesia.
37. Summer solstice lines
38. Summer and winter solstice lines
In the Aristotelian or Pythagorean system, the summer solstice lines are mirrored by winter solstice lines (see the diagrams on this page). Taking Alesia – the ‘hearth and mother-city of all Keltika’ – as the point of intersection, the corresponding winter solstice line runs north-west to the chief oppidum of the Senones (the Camp du Château near Villeneuve-sur-Yonne), to the Mediolanum that became the capital of the Aulerci Eburovices (Évreux) and to the cape beyond the port of Le Havre that was known as Caput Caleti (the headland of the Caleti tribe). In the other direction, it runs by the foot of the greatest of the Helvetii’s sanctuaries, on the Mormont hill, and meets the original Heraklean Way at Arona on the banks of Lake Maggiore.
There is a thrilling sense of hidden mechanisms in seeing an abstract design function so efficiently as a guide to early Celtic history. Arona, where two solstice lines intersect, is known to archaeologists as one of the great cultural crossroads of protohistoric Europe. Beyond Arona and the fortress above the lake, the line passes through the village of Golasecca, which has given its name to the Golaseccan culture of the early Iron Age. It served as a bridge between the Etruscans of Italy, the Hallstatt civilization beyond the Alps and the rich t
ribes of the Marne and the Moselle famed for their chariot-burials. This was the cultural equivalent of Alesia to the north-west, and so it appears on the Heraklean grid. Continuing to the south-east, the line arrives in the centre of the Mediolanum which is now Milan.
To complete the pattern, two further winter solstice lines should run to the north and south of the Alesia line. But even allowing greater margins of error (up to one degree and one minute of daylight), there are few signs of the same coherence. The contrast is revealing: both lines lie outside Celtic and Belgic Gaul. The northerly line, beyond the Rhine, passes close to some of the biggest oppida in Europe – Magdalensberg, Biberg and Donnersberg – but with nothing like the same precision. Although the Romans exaggerated the cultural differences of ‘Germanic’ tribes, many of whom were clearly Celtic, their history is different from that of the Gaulish tribes, and they may never have accepted the jurisdiction of the Druids. (Caesar was told that there were no Druids in Germany.)