One year later, at age 21, he was awarded a doctorate degree in history with the thesis "La Monarquía en Asturias, León y Castilla durante los siglos VIII al XIII.

During that time, he took a hiatus from his academic pursuits to join the newly-established republican government and served in the Spanish Cortes as a representative from Ávila and later in several other prominent posts, including Minister of Education.

He also emphasised the emergence in Spain of a free peasantry in advancing the frontier regions during the Reconquista that complicated the development of serfdom and hierarchical structures of lordship that historians described elsewhere in feudal Europe.

This conviction about the origins of a unique Spanish national identity led to a notable academic feud with another scholar in exile, Américo Castro, who had moved to the United States and taught at Princeton University.

Sánchez-Albornoz, who regarded Castro's interdisciplinary, literature-focused methodology as insufficiently rigorous and scholarly, responded with a new study, España: un enigma histórico (1956), which argued for the persistence of a pre-Arab Spanish culture and national identity, which were grounded in the reproduction of key legal, political and economic institutions.

Few academic historians today still subscribe to Sanchez-Albornoz's ideas about an essential national Spanish "character" that motivates history, but there is still a lively scholarly debate over convivencia as a historical model for understanding medieval Spain.

[2] Archived 2012-07-07 at the Wayback Machine Sánchez-Albornoz was survived by two daughters and a son, Nicolás (born 1926), who went on to become a noted scholar of Latin American demographic history and the author of La población de América Latina (1973, trans 1974, frequently republished).