The Duchy of Cantabria (Spanish: Ducado de Cantabria, Cantabrian: Ducáu de Cantabria) was a march created by the Visigoths in northern Spain to watch their border with the Cantabrians and Basques. Its precise extension is unclear in the different periods, but seems likely that it included Cantabria, parts of Northern Castile, La Rioja, and probably western areas of Biscay and Álava.
The two main towns of Cantabria before its conquest by the Goths were Amaya (in northern Burgos) and the City of Cantabria, believed to have been near modern Logroño. Both towns were destroyed in 574 by Liuvigild, who massacred many of their inhabitants. The legend of this destruction remained for long in the memory of the affected peoples. Bishop Braulio of Zaragoza (631-651) wrote in his Life of St. Emilianus how the saint prophesied the destruction of Cantabria because of their alleged sins. It is held in popular belief that the converted refugees from the City of Cantabria founded the monastery of Our Lady of Codés in Navarre.
A Senate of Cantabria mentioned in the Saint Aemilianus' work bears witness to a local nobility and a governing diet that may have been of the last independent Hispano-Roman provincial authorities. Some names are provided too, such as autochthonous Sicorius or Tuentius, with no clear ethnic affiliation, and Latin names Honorius and Nepotianus.
In 581, right before major Frankish expeditions against the Basques and the establishment of the Duchy of Vasconia under Frank suzerainty, the count of Bordeaux Galactorius is cited by the poet Venantius Fortunatus as fighting both the Basques and the Cantabrians, while the Chronicle of Fredegar brings up a shadowy Francio duke of Cantabria ruling for a long period some time before Sisebut's successful campaigns against Basques and Cantabrians. Archaeological discoveries in the last decades around the millennium have brought to light that the cultural and economic influences, and even small groups of people in the near Basque territory once part of the duchy or limiting with it, came from way beyond the Pyrenees during this time gap of political vacuum or at the best, uncertain authority.
In the late Visigothic period, at a second stage after the 6th century Cantabrian defeat, the Duchy of Cantabria is attested as being a buffer zone bearing witness to continuous fighting between Visigoths and Basques. In 670, the Visigothic king Wamba was campaigning there against the Basques when he heard of a rebellion in Septimania. Notice of a certain duke Peter of Cantabria, father of Alfonso I of Asturias, is attested on 9th century Asturian documents for the first years of the Umayyad conquest of Hispania.
- Collins, Roger (1983). Early Medieval Spain. New York: St. Martin's Press. p. 106. ISBN 0-312-22464-8.
- Douglass, William A. Bilbao, Jon (2005) . Amerikanuak. Basques in the New World. Reno: University of Nevada Press. p. 29. ISBN 0-87417-625-5.CS1 maint: multiple names: authors list (link)
- Alzualde, A.; Izagirre, N.; Alonso, S.; Rivera, N.; Alonso, A.; Azkarate, A.; de la Rúa, C. (1 January 2007). "Influences of the European Kingdoms of Late Antiquity on the Basque Country: An Ancient‐-NA Study". Current Anthropology. 48 (1): 155–162. doi:10.1086/510464. JSTOR 510464.