It comes from the Latin word (H)Iberus . This term has been mentioned since ancient times by different historians and geographers, both Greek and Latin.
Titus Livy: " cis Hiberum Hipania predomita erat ", Pliny the Elder: " Hiberus amnis, navigabili commercio dives" "Hibero " or Julius Caesar: " flumen Hiberum" (Segura, 2001: 16,59,60,119), among others, generally call it Hiberus (Hiberum). For his part, the Latin poet Avieno in his well-known poetic work "Ora Martima" mentions him as Hiberus .
The Calahorran poet Prudentius (348-415) in his song dedicated to the martyrs Emeterius and Celedonius calls the river " nos Vasco Iberus ". And finally, the poet from Bordeaux Paulinus (353-431), in his work "Peristephanon", calls it hiberus .
Alberto González Rodríguez in his Diccionario etimol gico de la toponimia mayor de Cantabria, besides pointing out that it was named for the first time in the periplus of Scylax around the 5th century BC, tells us the following: "In order for the Romance form Ebro to be possible, it is necessary to follow the Greek accentuation -something that according to M. Pidal, happens with truly popular terms- (...) Our place names Valderrible and Fontibre both suppose the noun Iberus with an inflected -e ending of the Latin genitive in -i (...) Both place names are compound words using the same morpho-syntactical procedure: modified noun (fonte, ripa) modifying noun in the genitive ( Iberi ). * Fonte Iberi 'the source of the Ebro' and Ripa Iberi 'the bank of the Ebro'.
Mikel Belasko in his Etymological Dictionary of the Names of the Mountains and Rivers of Navarre points out that the name frequently appears in Arabic documentation as Abroh and Ibro .
In medieval documents, it can be found in various forms: (H)Ebro, (H)Iberum, Ibero, Iberis, Hiberim, (H)Iberi. These are some of its first appearances: in 917 it appears as Ebro in the cartulary of Cardea (Lbano, 1996: 374) and in this form it also appears in the cartulary of San Mill n in 1045 (Ubieto, 1976:231). In the cartulary of Leire it appears as flumen Hyberum in 1047, Hebro in 1072 and flumen Hiberim in 1085 (Duque, 1983). Iberis flumen , in the year 1012 in the Charters of the town of Nava de Albura, collected by Llorente in the 3rd volume of his "Historical News" (Lbano, 1996: 80). And also with the form flumine Ybero we find it in a text of a donation to the monastery of Irache in 1067 (?) (Lacarra, 1965). From the 12th century onwards the current form Ebro became widespread.
Although much has been written about its etymology, it is not clear and there is no unanimity in this regard. Here we collect the summary made by Alberto González on the origin of the name (González, 1999: 153-156): "Leaving aside the fantastic interpretations that want to relate it with the legendary king son of Tubal, the god Bel or Phoenician words Ibrin/ Eberim ('end, end, extreme'), the hypotheses launched on the etymology of the radical Iber- are:
- From the Celtic Ber 'water stream', 'ravine'. This radical is well represented in the territory considered as Celtic (M. Dol).
- Belonging to the pre-Indo-European Mediterranean substratum, the Greek borrowed it and used it as a gentilic and as a phytonym to name watercress, a plant that grows in humid places, a meaning related to the primitive 'marshy lands' (Fletcher).
- From Basque Iber 'stream of water', parallel form to ibar/ibai d whose derivatives ibaica , ibaia mean vega and r o.
- From the Iberian vaika 'vega', derived from vai 'r or', although without excluding a clear relationship with Basque".
For his part, Antonio Tovar , in agreement with other authors such as Humboldt, C. Battisti and N. Holmer, whom he cites, states that the name of the Ebro comes from the hydronym Iberus flumen (Iberus - Ebro) which he explains from the Basque ibar (ra, estuary), or ibai (river). Adding that the appellation ibar in the mouths of Ionian-Greek sailors and merchants could have become Iberus (>Iberian, river).