The Comet in the Year 1018

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In the Middle Ages, comets and other natural phenomena were often seen as omens. Indeed, some important battles or changes of power were heralded by a comet in the skies. The best-known example comes from the year 1066, when Halley’s comet appeared in March, and the famous Battle of Hastings followed in October. King Harald Godwinsson was killed and William the Conqueror took the throne of England.

Another battle in that same century has also been associated with the appearance of a comet. In 1018, the German emperor and the bishop of Utrecht set up a military expedition to punish the insurgent count Dirk III of Holland. However, their professional army was defeated mercilessly in the peat bogs. This Battle of Vlaardingen, on July 29, 1018, was the start of Holland’s independency.
Medieval accounts mention a comet in that same year 1018. It stood in the northern skies and it had an exceptionally long tail. The written sources do not agree upon the exact timing: according to some occurred before the day of the battle, while others say it was seen afterwards. This article attempts to find out whether or not this comet was a genuine omen for the Battle of Vlaardingen.

The contemporary chronicler Alpertus of Metz gave a detailed description of the battle itself and also mentioned three celestial phenomena in that period, in three consecutive years: a lunar eclipse in the first year (end of 1016), a solar eclipse in the second year (just before Easter 1018), and a comet in the third year (1018). It should be noted that Alpertus used the Easter style, where the new year begins at Easter, and not on January 1. Alpertus said explicitly that the comet appeared after the battle of Vlaardingen. It was followed by wars and bloodshed among many nations. Alpertus did not specify this, but he may have referred to the capture of Kiev (August 14, 1018) and the battle of Cannae in Italy (October 1018).
Alpertus’ account seems reliable, because his two eclipses are corroborated by the NASA Eclipse Website. Several other contemporary sources, from Germany and Ireland, and even Japan, Korea, and China, reported a comet in the month of August or in the autumn of the year 1018. All this points at a comet that appeared after the Battle of Vlaardingen.

There are also medieval sources stating explicitly that the Battle of Vlaardingen was foretold by a comet that was visible during the four months preceding the battle. All these accounts can be traced back to the Chronicle of the Bishops of Cambrai, which was composed only a few years after 1018 and which is generally considered a very reliable historical source.

We do not doubt that there has been a comet after the battle, since there are so many independent accounts. Does this mean that there were two comets in one year, or is the Cambrai Chronicle wrong at this point? The latter seems to be the case. Close inspection of the Cambrai and the Alpertus texts shows that the author of the Cambrai Chronicle has probably read the account by Alpertus, and that he has misinterpreted the term ‘the third year’ as ‘one third of a year’, the four months following the solar eclipse at Easter 1018.
At first, is seems unlikely that the Cambrai author knew Alpertus’ work, since the two worked almost simultaneously, in the years 1021-1025. Also, it seems unlikely that the Cambrai author made a mistake because he must have witnessed the remarkable comet in 1018 personally and he must have remembered in which season it had appeared.
This can only be explained if we assume that the note regarding the comet in the Chronicle of Cambrai is a later (post 1025) addition to the manuscript. Unfortunately, this cannot be established, since the original manuscript has been lost. We don’t know whether these specific words were written by a different hand. It is likely though, because it has been established that there have been some additions to the Chronicle in 1051-1054. Furthermore, the Chronicle usually presents the events in a strict chronological order. The note about the comet, however, is placed after the description of the Battle of Vlaardingen and its aftermath.

Thus, an author who had not witnessed the comet in 1018 himself but who did know the work of Alpertus of Metz made and additional remark in the Chronicle of the Bishops of Cambrai, about a comet that was an omen for the Battle of Vlaardingen. Various medieval chronicles have copied this addition, and probably they did so eagerly, because it made their story more juicy. However, we must conclude that in reality there has been no comet foreboding the Battle of Vlaardingen, but only one that appeared after the battle had been fought.

The full article was originally published in 2015 in Terra Nigra, magazin of Helinium, AWN (Archeologische Werkgemeenschap voor Nederland):
Nieuwenhuijsen, K., De komeet uit het jaar 1018, Terra Nigra 188, 2015, p. 37-42.

© Dr. Kees C. Nieuwenhuijsen

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