Sequani (Coligny) Calendar


When the Romans invaded Gaul, they made it law for the people to use the Julian calendar. Despite this the Sequanii tribe, kept the old lunisolar calendar of the ancient Celts alive right up to the second century. How do we know?

In 1897 at Coligny (near Lyon) an amazing discovery was made. The Coligny calendar is a peg calendar made in Roman Gaul circa 2nd century AD, giving a five-year cycle of a lunisolar calendar with intercalary months. It is the most important evidence for the reconstruction of an ancient Celtic calendar. It is written in Latin inscriptional capitals in Gallic.

It was discovered in 73 fragments, along with the head of a bronze statue of a youthful male figure. It has been painstakingly restored, forming a 5 foot wide, 3.5 foot high bronze tablet. When assembled, it displays a lunisolar calendar, which follows both moon phases and the time of solar year.

It is believed that the calendar, dating back to the 2nd century AD, had been banned by the Romans as it indicated druidic practices. It is likely that the calendar was discovered by the Romans, who broke it up to prevent its use. The calendar can now be found at the Gallo-Roman Museum of Lyon. Since months were repeated, the missing months appeared at least once, enabling researchers to complete the missing pieces of the calendar. The restored tablet contains sixteen vertical columns, with 62 months distributed over five years.

The age of the calendar has been estimated based upon the styling of the letters and images it contains. French archaeologist, J. Monard, has speculated that the Celts created the calendar as a means of preserving the Celtic tradition of timekeeping at a time when the Julian calendar was being heavily promoted throughout the Roman Empire. Druids were members of the educated, professional class among the Celtic peoples of Gaul, Britain, Ireland, and possibly elsewhere during the Iron Age. The Druid class included law-speakers, poets and doctors, among other learned professions, although the best known among the Druids were the religious leaders.

A similar calendar found nearby at Villards d’Heria, but only eight small fragments exist of this.

Importance to us today

This calendar is relevant to us today. Since the ancient Celts placed such importance on the calendar and used it in defiance of the Romans, then as custodians of ancient traditions, we have a responsibility to preserve the calendar for future generations. The Druids were Astrologers and links have been made between stone circles aligning with the summer solstice (e.g. Stonehenge) and features of the night sky (Tara aligns with the moon in Scorpio) and the Coligny calendar. We know that lunar and solar phases were very important to the Celts and should be to us.

Knowth Calendar Stone

This stone engraving is found at the Knowth site in Ireland. According to Martin Brennan author of ‘Stones of Time’ it is a graphical depiction of a lunar calendar operating on the same principle as the Coligny Calendar found in France. It shows all 29 phases of the moon. The spiral covers up those three days when the moon is not seen. The included diagram shows how the centre squiggle in the drawing could be used to measure the 62 month span of the Coligny calendar. The author is only guessing that this calendar begins with the spring equinox.

Druid Months and their Meaning

In spite of its fragmentary state, the calendar can be reconstructed with confidence due to its regular composition. Each month is marked either MAT (complete) or ANM (incomplete). The first half of the month was always 15 days, but the second half would be 14 or 15 days. MAT months are 30 days, and ANM months are 29. An exception is the 9th month Equos, which in years 1 and 5 is a month of 30 days but in spite of this still marked ANM.

The middle of each month in the Coligny calendar is marked ATENVX which means ‘the returning night’. In fact, the splitting of each month in two is the precedent of the modern day fortnight.

There is much debate about when the Celtic months started. I have personally reached the conclusion that the month began with the moons first quarter. This is because the second half of the month would be darker when the moon is never more than a crescent. Other ancient lunar calendars start with the first visible crescent after the new moon, such as the Hijra calendar and this seems to be pretty universal in the ancient world.

Other ancient calendars, such as the Hebrew lunisolar calendar (still used today to calculate religious holidays, such as the Passover on Nissan 14th), which was also a lunisolar calendar also started the months on the first crescent. This calendar was heavily influenced by the Babylonians, with months being named after Babylonian Gods such as Tammuz. See link for further details.

However, Pliny the Elder says the following about Druids; “Mistletoe is rare and when found it is gathered with great ceremony, and particularly on the sixth day of the moon…. Hailing the moon in a native word that means ‘healing all things..” This indicates that the month was hailed in on the sixth day (compared to other ancient cultures), which would be the first visible crescent.

The Coligny calendar actually has markings that indicate that held holy festivals were held in the middle of the month (at the time of returning night) after the second quarter moon. The Coligny calendar marks a three day festival starting on the 17th day in the month of Samonios.

The total of 1831 days is very close to the exact value of 62 × 29.530585 = 1830.90 days, keeping the calendar in relatively good agreement with the synodic month (with an error of one day in 50 years), but doesn’t reconcile the lunar cycle with the tropical year. This meets with poor accuracy. Over five tropical years there is an error of 4.79 days (corresponding to 5 × 365.24219052 = 1826.21 days).

However, Pliny’s Naturalis historia (book 16) mentions a 30 year cycle used by the Celts. If one intercalary month is dropped every thirty years, the error is reduced to one day in 195 years. This would be addressed by reducing the month of Equos to 29 days in year 195.

Meanings of the Months

Whenever you look into the meanings of the months and when the year started, you face a huge debate.

Peter Schrijver in Studies in Celtic Historical Phonology states that the common Celtic root of Samo is “summer”, and Samonios is related to the old Irish Cetamuin “Month of May”, “First of May”, “May Day”. So the dates marked on the Coligny calendar mark a mid month celebration of the start of summer, corresponding to Beltane. Other scholars such as Professor Ronald Hutton concur that Samonios marks the beginning of summer.

However, looking at the meanings of other months, such as Ogronnios, which would subsequently tie in with October, means “Cold Month”, I think it is more likely that Samonios means “Summer’s End” and is the month in which Samhuinn would be observed. This is still a three day observance today, with its Christianised counterpart All Hallows Eve or Halloween. Interestingly, the Coligny calendar starts with an intercalary month. The Celts saw time in cycles. A circle has neither beginning nor end. It is continuous, so although modern pagans celebrate a New Year at Samhuinn, the wheel of the year is without beginning or end. It is a perpetual cycle, so New Year would be meaningless, but the celebrations were marked out.

These then are the months and their probable meanings in the Coligny calendar: –

These translations draw from a number of sources, but are not infallible.

In summary: –

  • the Coligny Calendar was a lunisolar calendar used by the ancient Celts and it is likely that Celts in other areas used a similar calendar with intercalary months every two and a half years.
  • The calendar month was split into two parts, the first being from the first quarter of the moon up to the second quarter moon on the 15th day of the month. The second half of the month was either 14 or 15 days.
  • There is a lot of difference of opinion about the calendar, but the ritual noted in Samonios indicates a 3 day festival around the moon’s second quarter and ties in with the modern day Samhain (or Halloween).
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