Extent of worship

The theonym Bandua has been found recorded in Portugal and Galicia. Along with Cosus, Nabia and Reo, Bandua is one of the best documented deities in large areas of western and north-western Iberia: six epigraphies from the Province of Ourense.^[7]

It has been proposed that the worship of Bandua spread from the north (Gallaecia and Asturia) into the south (Lusitania), along with that of Cosus and Nabia,^[8][9] so contrasting with the worship of Reo that would have extended in the opposite direction.

According to scholars Jürgen Untermann and Blanca María Prósper, the form Bandue, and the form Bandua or Banduae, predominate in the Galician territory north of the Douro River, while the Bandi ~ Bande form is more common in the Lusitanian area to the south.^[10][11]

Professor Olivares Pedreño argues that, in relation to the attestation of epithets Roudeaco/Roudaecus, the name pertains to a place named uicus Rouda, and their discovery in different locations suggests a migration or population displacement.^[12]

Possible water deity

Bandua has been associated with water^[13] in order to explain the hydronym Banduje, in Portugal, or the toponym Banhos de Bande (a thermal spot whose medieval name, Vanate, is unrelated)^[14] and the proposed^[13] relationship of the name with fords.

Polish linguist Krzysztof Tomasz Witczak also sees some possible cognate relationship between Lusitanian Bandua and Illyrian god Bindus, a deity of water sources also equated to Roman Neptune.^[15]

Possible protective deity

Their epithets seem to allude more to dwelling places, at least those containing the element -briga or -bris, "fortress": Lanobrigae, Aetobrigo, than to the worshipping communities themselves.^[16][17][18] In the same vein, Olivares Pedreño, while calling Bandua a male deity, noted that their name is attested with place names (e.g., Etobrico, Brialeacui, Isibraiegui, Longobricu, Veigebreaego, Lansbricae), which seems to indicate its relation to ancient vici and castelle - locations distant from romanized population centers.^[19] In a later article by Olivares Pedreño, this association seems to highlight their connection with local indigenous communities, as their protector.^[20]

Divine pair

The "location theory" has been criticized by de Bernardo Stempel,^[21] who interprets what have traditionally been considered singular thematic datives of male attributes as plural genitive forms referring to groups of people (B'andue Aetobrico(m), Cadogo(m), Roudeaeco(m), Veigebreaego(m)). She also states that they depend on a theonym, Bandua, which would be feminine as a consequence of the above, and which was probably created later than its masculine counterpart. Thus, we would have a pair of deities, Bandus (male) and Bandua (female), comparable to other Celtic pairs like Bormanos & Bormana, Belisama & Belisamaros, Camulos & Camuloriga and Arentius & Arentia.

Other interpretations

In a 2000 article, María Prósper offered another etymology: a reconstructed stem *bandu- would account for variations Bandue, Bandi and Bandei, ultimately deriving from Proto-Indo-European *gʷem-tu-. Thus, she argued, they are a deity of passageways, akin to Roman Ianus.^[22]