The purpose of this article is to review the historiography of anti-seigneurial conflict during the Late Middle Ages in Castile. The study of social conflict and especially anti-seigneurial conflict was one of the main interests of study of the late Professor Julio Valdeon. Thirty-five years have passed since the publication of one of his major works in this field, Social Conflict in the Kingdom of Castile during the 14th and 15th Centuries. In tribute to Professor Valdeon, this article looks again at his work on anti-seigneurial conflict, studies the evolution in the historiography, and poses a series of questions to further the analysis of this problem.