The methods of physical anthropology and ethnography were invoked to substantiate a Basque essentialist identity discourse: the biological characteristics of a supposed Basque race were aligned with cultural characteristics (language, beliefs, social practices, etc.).
Basque folklore and traditions had been described from the late 18th century onwards. Juan Ignacio Iztueta (1767–1845) described dances in Guipuzcoa province; Manuel de Larramendi (1690–1766), Augustin Chaho, many foreign travellers, and participants of the fuerista movement emphasized various peculiarities of the Basques, for example the language, fueros (charters), history or religiousness. Additionally, some dictionaries published during the 19th century contained abundant Basque ethnographic material, such as the work of Pascual Madoz (1806–1870). Likewise, the English writer Wentworth Webster compiled a book of Basque legends, collected chiefly in the Labourd (1877). One of the areas of interest of the Asociación Euskara de Navarra (Basque Association of Navarre, founded in 1877) was ethnography. Furthermore, articles on this subject appeared in Basque journals, such as Euskal-Erria (1880-1918).
Eminent foreign scholars, including the French anthropologist Paul Broca, had already carried out craniometric studies of Basque skulls in the middle of the 19th century. Around 1900, Basque physical anthropology began to flourish. Telesforo Aranzadi (1860–1945), university professor in Barcelona, member of various scientific institutions and founder of Basque anthropology, published on issues such as the supposed Basque race, sports and agricultural tools. His colleague, the archeologist Enrique Eguren (1888–1944), was among the founders of the Spanish Society of Anthropology, Ethnography and Prehistory. José Miguel de Barandiarán (1889–1991), the “patriarch of the Basque culture” and the outstanding disciple of Aranzadi, studied ethnology as well as Basque toponymy, mythology, legends, etc. He took part in international ethnological congresses, was a member of academic institutions such as the Société Française d’Ethnographie, and published prolifically in the field as of the 1920s.
Between 1917 and 1936 (the outbreak of the Civil War) Aranzadi, Eguren and Barandiarán carried out research together, dovetailing ethnology and archeology. During the Franco period, Julio Caro Baroja (1914–1995) became one of the leading figures of Basque ethnography.