We analyze the military career of Ángel de Saavedra Ramírez de Baquedano, the third Duke of Rivas since 1834, and their participation in the Peninsular War. In addition to the research of a little-known facet of that historical character, we provide the data needed to understand the initial impression of liberalism on his thinking, considering that his military career just led him to reside in Cadiz during the Spanish Parliament activity, and we characterize their patriotic poems and glorification of the liberal system, first works of whom will eventually become an influential politician and, above all, one of the Spanish writers of major reference.; Analizamos la trayectoria militar de Ángel de Saavedra Ramírez de Baquedano, desde 1834 ter...