It has been a century since the publication of the book Iglesias Mozarabes (1919), the most important study around the High Medieval Hispanic Architecture. Our article summarizes its methodological basis, considering both the ideological perspective of its author and the institution that supported it: GomezMoreno and the Centro de Estudios Historicos. Our main conclusions allow us to frame this book in the general renewal experienced by Spanish science during the first two decades of the 20th century. Gomez-Moreno should be considered the first researcher to apply multidisciplinary approaches to the study of historical Architecture. In addition, the book presents the cultural activity of the so-called "Mozarabs" as another step in the formation of the Spanish identity deeply influenced by Eastern civilizations.