Mithras

For the first time we have published this idea in: Himmelsscheibe, Sonnenwagen und Kalenderhüte – ein Versuch zur bronzezeitlichen Astronomie. Acta Praehistorica et Archaeologica 40, 2008, S. 93-126, insbesondere S. 105-106.

At the end of the 1st century a new exotic cult appeared in the Roman Empire - the Mithras cult. The name refers to the Persian sun god Mithras. In Persia, however, there was no cult of the sun god Mithra that resembled the later Roman cult. Merkelbach suspects a creation of the cult from the surroundings of the imperial house. We would associate the idea of the cult with the procession of Tiridate. The new Armenian ruler moved through the Roman Empire with a troop of thousands of Parthian horsemen. In gold-decorated Rome he threw himself at Nero's feet, worshipped him as his god Mithra and received his reign from Nero. Through this propagandacoup a threatening war between Rome and Parthia for the rule in Armenia could be prevented. As a sign of the solidarity between the two peoples, there could have been an agreement that a Persian god should also be worshipped in Rome.
The cult image of the bull-killing Mithras gives puzzles away. This picture cannot be understood from Persian mythology - but from the Roman imperial propaganda: Since Julius Caesar the Roman rulers increasingly connected their power with the sun. Thus the Egyptian solar calendar was introduced by Caesar in Rome, Augustus sacrificed Apollo after his decisive victory in Actium and erected an Egyptian obelisk as a sign of victory and pointer of a sundial in Rome. Nero received Tiridates disguised as sun god and Aurelian introduced in the 3rd century the December 25th as feast day of the invincible sun god in Rome.

In the Mithras relief, the sun-god kills a bull, that is curved to a (thick) crescent moon. The portrait is full of astral allusions. It is often framed by the zodiac and the participating animals partly represent the celestial equator. The zodiac and celestial equator together symbolize the whole cosmos, which is dominated by the sun god. In the calendar the sun replaces the triad sun, moon and stars. In a Babylonian leap rule, which enjoyed wider distribution, the thickness of the crescent moon in the Plejades in the constellation of Taurus in the supposed spring month is used to conclude the necessity of switching on a month. Thus sun, moon and stars (in particular the Pleiades) regulate the calendar and thus the order of the sky. However, this regulation had begun to waver around 500 BC. Due to the precession of the Earth's axis, the validity of the leap rule moved slowly from the spring month towards summer. An adaptation of the leap rule in the spring month would have led to a thicker moon crescent, than indicated in the Babylonian tradition. If one measures the cult images of the Mithras, then quite uniform "thicknesses" of the moon crescents result from the bull body. Converted into the age of the moon they correspond to a lunar thickness, which one would have had to use adapted in this time for the Babylonian leap rule - which however would have been clearly wrong for all experts. Thus the cult picture symbolizes the "falling" switching rule to the initiate and thus the failure of the triad moon, sun and stars. Only the sun alone could be relied upon. Thus the Mithras cult supports the supremacy of the sun over all other gods and thus also the legitimacy of the emperors, who increasingly referred to the sun. Just as the sun orders the cosmos, so does the emperor on earth. The Mithras cult was thus appropriated for the rule of the emperors - the Mithras relief contributed its part to this.

Various Roman cults have special references to astronomy. For contemporaries, this is most evident in the external presentation of the corresponding works of art. They represent a popularizing short form of the cult. A nice example is the Mithras cult.
At the end of the 1st century it appears with many astronomical references. The name refers to the Persian Sun god Mithra. In Persia, however, there was no cult of the sun god Mithra that resembled the later Roman one. Merkelbach suspects that the cult was created by the environment of the imperial house. We see the idea of the cult in connection with the procession of Tiridate. The new Armenian ruler marched through the Roman Empire with a retinue of thousands of Parthian horsemen. In gold-decorated Rome he threw himself at Nero’s feet, worshipped him as his god Mithra and received his dominion from Nero. Through this propaganda coup a threatening war between Rome and Parthia for the rule in Armenia could be prevented. As a sign of the bond between the two nations there could have been an agreement that a Persian god should also be worshipped in Rome.
The cult image of the bull-killing Mithras poses a riddle. This image cannot be understood from Persian mythology – but from Roman imperial propaganda: In the Mithras relief the Sun god kills a bull that is curved to a (thick) crescent moon. The image is full of astral allusions. It is often framed by the zodiac, and the animals involved partly depict the celestial equator. The zodiac and the celestial equator together symbolize the whole cosmos, which is dominated by the Sun god. In the calendar system the Sun replaces the triad of Sun, Moon and stars. In a Babylonian leap year rule, which enjoyed widespread popularity, the thickness of the crescent moon in the Pleiades in the constellation of Taurus is used to refer to the necessity to insert a leap month. Thus the Sun, Moon and stars (especially the Pleiades) regulate the calendar and thus the order of the sky. However, this regulation had begun to collapse around 500 BC. Due to the precession of the earth’s axis, the validity of the leap year rule slowly moved from the spring month towards summer. An adjustment of the leap year rule in the spring month would have led to a thicker crescent moon than indicated in the Babylonian tradition. If one measures the cult pictures of the Mithras, then quite uniform “thicknesses” of the moon crescents from the bull body result. Converted into the age of the Moon they correspond to a Moon thickness which one would have adapted in this time for the Babylonian leap year rule – which would have been clearly wrong for all experts. Thus the cult image symbolizes to the initiate the “falling” leap year rule and thus the failure of the triad of Moon, Sun and stars. Only the Sun alone could be relied upon. The bull-killing Sun god Mithras kills his competitors and thus makes the change in the calendar and the heaven of the gods visible for all. Thus the Mithras cult supports the supremacy of the Sun over all other gods and thus also the legitimacy of the emperors, who increasingly relied on the Sun.

Over the course of the second century CE, worship of the Persianate god Mithras swept across the whole of
the Roman Empire. With its distinctive traces preserved in the material record—including cave-like sanctuaries
and images of Mithras stabbing a bull—the cult has long been examined to reconstruct the thought-systems
of Mithraism, its theology, through such monumental trappings. This volume starts from the premise that, like
much “religion” in the Roman world, the cult of Mithras must be examined through its practices, the ritual
craft knowledge which enabled those rites, and the social structures thus created. What did Mithras-worshippers
do? How do we explain the unity and diversity of practices observed? Archaeology has the potential to
answer these questions and shed new light on Mithras-worship. Presenting new discoveries, higher resolution
archaeological data on finds and assemblages, and re-evaluations of older discoveries, this volume charts new
paths forward in understanding one of the Roman Empire’s most distinctive cults.

The exhibition “The Mystery of Mithras: Exploring the Heart of a Roman Cult” is being presented at the Musée royal de Mariemont from 20 November 2021 to 17 April 2022, then at the Musée Saint-Raymond de Toulouse from 14 May 2022 to 30 October 2022, and lastly at the Archäologisches Museum Frankfurt from 19 November 2022 to 15 April 2023.

The catalogue prepared for these different venues pursues three main objectives: proposing, thanks to the contributions of some 75 international experts, a new synthesis for a complex and fascinating cult that reflects the remarkable advances in our knowledge in recent decades; promoting by means of high-quality illustrations numerous monuments, both famous and unknown, that represent so many pieces of the giant Mithraic puzzle; lastly, to restore Mithras to his proper place in the religious landscape of yesterday and the European culture of today. For ordering the catalogue: accueil@mariemont.be

The National Museum of Rome has an important collection of Mithraic sculptures found in the years 1973-1975 during the archaeological excavation under the early Christian basilica of Santo Stefano Rotondo on the Caelian hill in Rome. The sculptures excavated from this Mithraeum show many traces of gilding and polychromy, whose best example is the great bas-relief with Mithras slaying the bull discussed in this work. The analysis was conducted during a scientific campaign in the museum with portable instrumentation of the Institute for Conservation and Valorisation of Cultural Heritage, ICVBC mobile laboratory following a completely non-invasive approach. By means of a protocol based on the use of multispectral imaging, microscopy, X-ray fluorescence (XRF) and fiber optic reflectance spectroscopy (FORS), this study allowed to better understand the technique used and to make comparisons with other representations of Mithras slaying the bull.