The writing of history in 19th-century Portugal was inherently linked to the notion of Regeneração (“Regeneration”). Historians would later use this word to describe the post-1851 period in Portuguese history, marked by relative political and socioeconomic stability – in comparison with the turbulent , punctuated as it had been by the Napoleonic invasions (1807-11), the transfer of the royal court to Brazil (1807), the independence of Brazil (1822), and the successive revolutions and civil wars that accompanied the establishment of a constitutional regime. However, Regeneração was also the word that liberal intellectuals – and among them, historians – used for a desire to “return to origins”. This desire was deeply entrenched in a Romantic mentality, which looked to the past as a basis for restoring or reviving the “declining and feeble” Portuguese nation.
Among these historians, Alexandre de Carvalho e Araújo (1810–1877) stands out as one of the harbingers of Romanticism in Portuguese history-writing and fiction. A conservative liberal, Herculano participated in the military revolt of August 1831 against the absolutist restoration, following which he went into exile in England and France. There, he became acquainted with the works of , Walter and Victor , and historians such as Wilhelm von , , , , , , and .
In 1832 Herculano returned to support the liberal cause in the Portuguese civil war. After the victory of the liberals, he was invited in 1837 by the Sociedade Propagadora dos Conhecimentos Úteis (“Society for the propagation of useful knowledge”) to edit the literary journal Panorama. This periodical, with its considerable circulation of 5000 copies, contributed to the spread both of the and of historical accounts, which represented roughly a quarter of the contents. That was in large part due to the contributions of Herculano himself, but also of other authors such as António Feliciano de (1800–1875), who in 1839 published there his . In 1842, another journal, Revista Universal Lisbonense, founded by Castilho in 1841, published in its turn Herculano’s “Cartas sobre a História de Portugal”, inspired by Thierry’s (1827). In this work, Herculano first advanced his thesis that the Middle Ages had been a glorious period in Portuguese history, in contrast with the subsequent political, moral and socioeconomic decadence of the Early Modern period. Herculano reiterated this view in his “Cogitações Soltas de um Homem Obscuro” (“Wayward thoughts of an obscure man”, likewise published in the Revista Universal Lisbonense, 1846): national decadence is linked to Portugal’s maritime expansion. Although this thesis was not altogether new – it had been anticipated since the 16th century – it gained momentum in the 19th-century Medievalism of Romantic historiographical accounts.
“Cartas sobre a História de Portugal” formed the basis for Herculano’s , published in four volumes between 1846 and 1853. Planned to encompass most of Portuguese history, this work ended up being much more restricted in its temporal coverage, ending in the late 13th century with ’s reign. The was largely due to Herculano’s relative disregard for post-medieval history, but also to his other historiographical projects and the controversies raised by his debunking of national myths, notably the so-called “” (where a military victory in 1139 was believed to have been due to heavenly intervention). In addition to its solid documentation and method, the História de Portugal marked the introduction of economic, cultural, and mentality-historical perspectives. On the strength of this achievement, Herculano was made a member (and later vice-president) of the Lisbon Academy of Sciences, charged with the task of supervising the . Based on its , this collection of primary sources on Portuguese medieval history commenced publication in 1856 and went on well after Herculano’s death.
During his work on the Portugaliae Monumenta Historica, Herculano published (“History of the origin and establishment of the Inquisition in Portugal”, 1854-59). It painted a dark picture, linking the Portuguese Inquisition to the growing power of the monarchy since the 15th century.
Herculano’s main successor, Luís Augusto (1822–1871) also combined the writing of history and of historical novels. In 1859 he became one of the first lecturers of the newly created Curso Superior de Letras, the first higher-educational curriculum in Portugal exclusively dedicated to the study of history, philosophy and literature. In works like (1860) and (1868), Rebelo da Silva drew on Herculano’s theories on the formation of the Portuguese kingdom and the causes of the nation’s decadence, but extended his predecessor’s period span and thematic coverage.
Although Portuguese Romantic historiography was largely liberal in orientation, certain more traditionalist authors also contributed to the field, e.g. Manuel Francisco de de Mesquita de Macedo Leitão e Carvalhosa (1791–1856), better known as the second Viscount of Santarém. Santarém saw his political career thwarted by his involvement in the absolutist governments of King Miguel (r. 1828-34), but left an important mark as a historian of institutions (, 1827-28), maritime expansion (, 1841) and diplomacy (Quadro elementar das relações políticas e diplomáticas de Portugal com as diversas potências do mundo, 1842-76). These works show the influence of Guizot, Ranke, and , a rigorous application of modern historiographical methods and, similarly to Santarém’s liberal counterparts, a strong belief that history could play a regenerative role in Portuguese society.