By the age of 30, Fernández Miranda had already served as a lieutenant for the Nationalists in the Spanish Civil War and begun a promising career as a law professor; that year, he earned a chair at the University of Oviedo, of which he would later serve as rector, 1951 to 1953. He was destined to make his biggest impact in public service, however. Franco chose him to serve as the government's Director-General of University Education in the mid-1950s, and gave him an even weightier assignment in 1960: Fernández Miranda was entrusted with the political education of Prince Juan Carlos, whom Franco had tapped to carry on as his successor as the King of Spain, after the death of the caudillo. After having endured years of military training, Juan Carlos credited Fernández Miranda with being the first of his tutors to teach him to rely on independent thinking. In the final years of the Francoist State - Franco would die 20 November 1975 - Fernández Miranda also played an important political role as a high-ranking member of the Movimiento Nacional, the Francoist State's only legal political party. He served as interim Presidente del Gobierno for a few weeks in December 1973, after the assassination of Luis Carrero Blanco. He had been Carrero Blanco's principal deputy prime minister. Although Fernández Miranda was one of the top candidates to succeed Carrero Blanco, the job of prime minister—Franco's last, as it would turn out—went to Carlos Arias Navarro.
Leader in transition
Shortly after Franco's death, Juan Carlos became king. He retained Arias Navarro as prime minister but, in a nod to his political mentor, named Fernández Miranda speaker of the Cortes and president of the Consejo del Reino in the transition government. In these roles, Fernández Miranda was able to push a willing king toward the development of a democracy. Fernández Miranda sought to establish a two-party system, with one conservative party and one liberal party. He suggested legitimizing the suppressed PSOE, which was leftist but anti-communist, for the liberal role. Upon Arias Navarro's resignation in 1976, Spain was still operating under Francoist law; it was Fernández Miranda's job, as head of the Council of the Kingdom, to suggest three names to the king for a new political leader. He placed the reformist Adolfo Suárez on his list, despite Suárez' relative inexperience. Suárez was duly selected, and soon called for a political reform law, to be followed by democratic elections, Spain's first in 40 years. The law professor Fernández Miranda, still serving as speaker of the Cortes, was the principal author of Suárez' Ley para la Reforma Política, approved by the Government in September 1976, by the Cortes in November 1976, and by a popular referendum 15 December 1976.
Enrique Fernández-Miranda y Lozana, 2nd Duke of Fernández-Miranda and Grandee of Spain on 3 November 1982, married on 12 May 1975 to María de los Reyes de Marcos y Sánchez, and had issue:
* Torcuato Enrique Fernández-Miranda y de Marcos
* Alvaro Manuel Fernández-Miranda y de Marcos
Fernando Fernández-Miranda y Lozana, married to Ana Allendesalazar y Ruíz de Arana, daughter of Carlos Allendesalazar y Travesedo, ?th Viscount of Tapia and a descendant of Maria Cristina of the Two Sicilies, and wife Ignacia Ruíz de Arana y Montalvo, 14th Marchioness of Velada, and had issue: