We have seen and heard many who are overwhelmed by such madness, carried away by such folly, that they believe and assert that there is a certain region called Magonia, whence ships come in the clouds: the which bear away the fruits of the earth, felled by hail and destroyed by storms, to that same country; and these sailors of the air forsooth give rewards to the weather-wizards, and receive in return the crops or other fruits. Certain ones have we seen, blinded by so dark a folly, who brought into an assembly of men four persons, three men and a woman, as having fallen from the said ships; whom they held in bonds for certain days and then presented before an assembled body of men, in our presence, as aforesaid, that they should be stoned. Howbeit the truth prevailed, after much reasoning, and they who brought them forward were confounded. (trans. Reginald Lane Poole)
What distinguishes this episode from many folklore tales of ships sailing in the sky is the availability of a precise reference, the authority of a known and respected historical figure who has written extensively on many other subjects, and the fact that the Archbishop, while he testified to the authenticity of a first-hand report, remained a skeptic about the reality of the objects themselves.
In 1969, Vallée was using anything and everything, no matter how specious, to concoct an ancient astronaut book. He only discovered Agobard because his story was embedded in an occult book Vallée both read and quoted at great length: The Comte de Gabalis (1670) of the Abbé de Villars. What passes for analysis of the weather-magicians and Magonia in the book that takes its name from the story is only a gigantic quote from Discourse V of the occult novel, along with material appearing in the 1913 end notes on the same.
Because Villars tried to fit occultism into the medieval idea of the four elements, Vallée becomes quite taken with the idea of sky beings and therefore follows Villars in making these Magonians into analogues of sky-demons called Sylphs, air elementals invented by Paracelsus.
In so doing, Vallée, that intrepid investigator into whatever occult books are easiest to access, missed other ancient references to the weather-magicians and the pagan beliefs that undergirded them. And of course it connects to the Watchers and the Nephilim.
This is a little tricky, so to try to make this a little simpler, I’ll try to put the material in chronological order rather than make it into a giant puzzle. Much of this discussion follows the research of Bernadotte Filotas, who discussed this in her book Pagan Survivals in 2005.
In pre-Christian Celtic areas, there were spirits called the Dusii that the Greeks and Romans equated with horny nature spirits like Pans and Fauns. Their name likely derives from Indo-European terms for disembodied spirits or vapors. St. Augustine is one of the first to describe them as demons, and he did so in rejecting the belief that the Sons of God were angels who mated with humans. Instead, such intercourse, he said, must have been with ethereal demons like the incubi and succubae:
These same demons, whom the Gauls name Dusii, are relentlessly committed to this defilement, attempting and achieving so many things of such a kind that to deny it would seem brazen. Based on this, I dare not risk a definitive statement as to whether there might be some spirits, aerial in substance (for this substance, when it is set in motion by a fan, is perceived as sensation within the body and as touch), who take bodily form and even experience this sexual desire, so that, by any means they can, they mingle with women sensually. (City of God 15.23, trans. Marcus Dods)
Now, granted, this doesn’t seem to have a lot to do with Magonians. Here’s where it gets interesting. The Dusii appear in the eighth-century Life of St. Richarius, where the author reports that the peasants of Gaul believed that the Dusii steal agricultural produce. Different editions of the text alternately name the Dusii as the dusi manes or the maones, a word corrupted from the Roman manes, or the souls of the dead. Stealing and destroying crops is exactly what the Magonians were said by Agobard to have done.
So how do we get from crop-stealing ethereal rapists to sky sailors? This is a weird one, but it relates to the odd way that early medieval people integrated pagan creatures into a Christian framework. Isidore can help us again, for he explains that in his day the “heathen” of Visigothic Spain believed that the manes lived in the sky: “They say manes are the gods of the dead, whose power, they assert, is between the moon and the earth” (Etymologies 8.11.100, trans. Ernest Brehaut). Filotas suggests that the story as we know it traveled into France from Spain in the wake of the Moorish conquest. In so doing, the sky-demons of local Spanish lore remembered by Isidore influenced the chthonic manes of old Gaul and became the Magonians of ancient astronaut fame.
It seems from what sources we have that the controversy over whether angels fell to earth to mate with women helped to give rise to the idea similar pagan demons were aerial rather than chthonic in nature, similar to the way the Book of Enoch reported that the disembodied spirits of the Nephilim were freed from hell but denied heaven, and therefore must have been creatures of the air, just as their fathers, the Watchers, were associated with the sky and the stars. That said, Christian sources are obviously biased, so the degree to which Christian theology impacted the lore of the manes or Magonians is open for debate.
At this point, we have assembled all of the pieces that Agobard encountered save one. By Agobard’s day, the flying demons who destroyed crops and raped women had become conflated with the Tempestarii, or weather-magicians, but a careful reading shows that Agobard’s peasants believed that the manes were in league with the weather-magicians, and not identical with them. These weather-magicians have Classical and Germanic roots, and they were famously condemned by Carolingian rulers like Charlemagne. The Germans carried the story eastward, and their final echoes can be seen in the Solomonarii of Transylvania, the evil weather-magicians who study in the Devil’s School, or Scholomance, remembered today almost entirely because Bram Stoker included the Scholomance in Dracula.
The interesting thing is that such an analysis eliminates the need to view the Magonians as either real sky beings or as survivals of ancient myths of rapacious thieving sky beings. They are simply an outgrowth of folklore, developed from apparently clear antecedents and changing over time as different stories, philosophies, and ideologies mixed together during the period when paganism gave way to Christianity.