After the Civil War, the agrarian sector in Spain underwent profound transformations. Decline and decadence were the main conclusions of the analysis, although historians have for a long time discussed the way this withdrawal occurred. The impact of these changes in land ownership resembled a closed topic, pointing to the end of the rentism. The case of the Dukes of Alba offers some singularities that modify this general outlook. On the one hand, they succeeded in maintaining a great part of their properties. On the other hand, they did not represent a perfect continuity with the past: they made outstanding transformations in order to gain profits. This article seeks to define what these changes were, why they decided to opt for them and the connection with wider transformations in the Spanish countryside. Luis Martínez de Irujo, Duke from 1953, was the main player in this evolution, more than a genius he was additionally a good interpreter of an age.