Lately I’ve been doing a lot of research into the gods of continental Europe, of the areas once known as Gaul and Germania, as well as those British gods we know from history and archaeology more than from literature and myth. I have a real fondness for these deities, along with other gods who traveled.
This makes sense, honestly, for me as someone who lives a good way away from the regions my gods first made themselves known. I’m similarly interested in the ways that communities introduce new gods, and the ways that deities accompany colonists to a new region. Gods and their migrations is clearly a topic of some interest.
A lot of what little we know about the gods of Gaul and (apart from Ireland and Wales, where a mythic literature survives) Britain is based on archaeology and linguistics. What this means is that much of our knowledge is dependent on what has survived and been discovered in and on the ground, usually in the form of imagery and (Latin) text inscriptions. This included not only temples (some gods had several, most had none that survived) but also such things as votive offerings which might have inscribed on them the name of the deity receiving them, altars raised in fulfillment of a vow made to a particular deity, and place-names that appear to honor a deity or indicate the presence of a worship site. Sometimes the linguistic and archaological evidence doesn’t match up–for example, the goddess Nantosuelta’s name would indicate a river connection but her strong association with symbols of abundance and prosperity (along with her large number of likely worship sites) suggests that she is far more than a river spirit. It may be that other gods we are familiar with from fewer sources originally had a wider range of associations than we know of as well.
In some cases a god was known across a wide geographical area. Epona was one such–the Romans themselves adopted her and there is, uniquely, evidence of her worship in Rome itself–but other gods were known in different regions as well, such as Belenos, Sirona, or Rosmerta. Others were most well-known in a particular area–for example, as goddess of the river Seine, Sequana tended to be worshipped most often near that river. Still others, tribal deities, have been attested primarily in regions where those tribes existed, although tribal territories sometimes moved and their gods did likewise. There are also gods we know of only from a single inscription or other archaeological find.
Here I’m going to talk a bit about Rome. I’m not myself (at least at this point in time–I’ve learned over the years to never say never) a follower of the Roman gods. Partly this is a conscious choice in that the Romans were very particular and detail-oriented about their worship, and I don’t think I’m personally a good match for that sort of system; partly I suspect it’s because I am already so connected with the Greek gods, and the Greek and Roman pantheons have a very complex relationship.
But about Rome. The Romans were travelers, that is one way to put it. On their travels they encountered many people, and along with these people they encountered their gods. And when it came to gods, the Romans had this thing called the interpretatio romano, which means, essentially, that they saw the gods they encountered as being their own Roman gods under different names. So if they ran across a Celtic god who was a healer, they figured that he was Apollo; if they found a war god, they assumed he was Mars, and so forth. So, Apollo Grannus is the Celtic god Grannus by way of the interpretatio romano. Mars Leucetius is the deity formerly known as Leucetius. And so on. (So, if this is the way your polytheism rolls, there is certainly precedent for it. :))
This was more common with male deities, although sometimes a Celtic goddess was associated with a Roman one (such as Sulis Minerva, patron goddess of the healing springs of what we now know as Bath). But often the Romans would take a Celtic deity couple, such as Borvo and Damona, and only the male deity would be given a Roman name to add on–thus, at some sites Borvo might become Apollo Borvo while Damona remained simply Damona.
To some extent the interpretatio romana is helpful to us in that it provides a bit of context that would otherwise be missing, since we lack a lot of information on Gaulish gods; knowing that, say, the Celtic Cissonius was known to the Romans as Mercury Cissonius lets us know that the Romans believed that Cissonius had something in common with the Roman god Mercury. On the other hand, we have no way of knowing exactly why the Romans thought that Cissonius was Mercury–Mercury has many associations including commerce, communication, and travel, and we don’t know which of these attributes may also have applied to Cissonius.
On the other other hand, it’s certainly arguable that becoming identified with Mercury made some changes to Cissonius’ character, and that Mercury Cissonius was a subtly different entity (or, at least, took a different role) than the “original” Cissonius. But that’s not quite what I meant to write about here, so I’ll let it pass for now.
Another thing the Romans did on their travels was grow their empire. Over the centuries the Roman Empire expanded from Rome itself all the way to Britain, on the way taking over great parts of Gaul, adding their lands to the Roman territories, and taking their citizens as part of their army.
These Gaulish soldiers took their own gods along with them when they travelled with the Roman army to other parts of the Roman Empire. Thus, when we have evidence of gods being worshipped in a variety of regions, we don’t necessarily know how that came to be, although in some cases (for example, when a god known to exist in what is now Germany is also attested at a Roman military site in northern Britain) it does seem to indicate that a soldier may have brought his gods along with him to his new posting.
So the issue here, for me, isn’t whether a god can move from one geographic region to another. Clearly there is evidence that the ancients believed that they could. It’s more a matter of how this happens–and of what happens when a god who was once strongly associated with a place is honored in a different place. For example, it seems likely that a healer goddess retains that ability whether or not she is called on at her own healing springs–the British Coventina, known for a spring near Hadrian’s Wall, is also attested in what is now France and Spain.
My own sense is that gods may begin as gods of place, but they don’t necessarily stay that way.