The hypothesis that the Basque language is genetically related to languages in the Caucasus region was developed in the 20th century by respected scholars including C. C. Uhlenbeck, Georges Dumézil, and René Lafon, but has recently fallen into disfavour. The author defends the Euskaro-Caucasian hypothesis in a refined model in which Basque (Euskara) is most closely related to the North Caucasian language family (but not “South Caucasian” = Kartvelian). It is maintained that this hypothesis is not only linguistically convincing, supported by hundreds of basic etymologies, sound correspondences, and shared morphology, but is also consistent with recent results in archaeology and human genetics. Among the Euskaro-Caucasian etymologies is a significant number involving small and large cattle, swine, dairying, grain and pulse crops, and tools and methods of processing crops. These lexical fields are consistent with the spread of agriculture and animal husbandry to Western Europe by means of colonisation by bearers of the Cardial (Impressed Ware) Culture who came from the Anatolian (or possibly Balkan) region, and spoke a language related to Proto-North Caucasian. The well-known genetic distinctiveness of the Basques is a result of centuries of low population size, genetic drift and endogamy, rather than purely Paleolithic ancestry. The present-day Basque people represent a genetic amalgam of the Cardial colonists with indigenous hunter-gatherers, but their Euskaro-Caucasian language is colonial, not indigenous, in origin. Basque is the sole remaining descendant of the Euskaro-Caucasian family in Western Europe, but there is evidence (in the form of substratum words) that this colonial language was formerly more widely spread in other nearby regions (Sardinia, parts of Iberia, France, the Alps, Italy, the Balkans, and perhaps beyond).