This article examines the renewal of Spain's corporate elite between 1920 and 2020 by combining Social Network Analysis with prosopography. Using interlocking directorate data for the two hundred largest Spanish firms, aggregated into three periods (1920–1950, 1960–1980, and 1990–2020), the study identifies the most structurally central directors and reconstructs their social origins, education, and career trajectories. The findings reveal that while the structural core of corporate power remained remarkably stable—between thirty-four and forty individuals per period, less than 1 percent of all directors—its social composition changed substantially. Aristocratic backgrounds and dynastic ties gave way to middle-class origins, public university credentials, and senior civil service careers. Two institutional channels drove this transformation: the state, whose role shifted from direct political overlap to technocratic circulation through public administration; and the public university system, which increasingly replaced inherited status as the basis of elite recruitment. Rather than democratization, renewal took the form of controlled circulation: new actors entered through selective pathways while the underlying power structure remained intact. By adopting an interpersonal perspective over a full century, the article addresses a persistent gap in the literature on interlocking directorates, which has focused mainly on firm-centered networks rather than their most central actors.