It would be hard to name a European chronicler whose work has a more pressing claim to dissemination to a wider audience than Fernão Lopes. The surviving chronicles, which were unquestionably authored by this ‘father of Portuguese historiography’ (or even, it has been said, of Portuguese prose), cover more than half a century (1357–1411) and amount to over half a million words, although it is unlikely that they represent his total output. A self-proclaimed pioneer in the use of archival documents to present historical truth, he also thought deeply about the construction and purposes of history.

Although little of his early life can be verified, Lopes must have been born around 1380, probably in Lisbon, of relatively humble stock. Trained as a notary, he rose high in the service of the new Portuguese royal dynasty of Avis, acting as librarian to the heir to the throne, Prince Duarte, before being appointed in 1418 by King João I (1385–1433) as keeper of the royal archives in the Torre do Tombo (Archive Tower) in the keep of Lisbon castle. It was here, 40 years earlier, that King Fernando I (1367–1383) had established a repository for the mass of documentary material that underpinned Portuguese royal government. The next two decades saw the responsibilities entrusted to Lopes steadily expand. Continuing to act as the king's ‘notary general’, he was also private secretary to one of João's sons, Prince Fernando, with whom he established a close personal relationship. When João died in August 1433, Lopes became secretary to King Duarte I (1433–1438), who on 19 March 1434 commissioned him to ‘set down in a chronicle the histories of the kings who had previously reigned in Portugal, up to and including the great and noble deeds of my most able and virtuous father [João]’; in return, he was granted an annual salary of 14,000 reais. This great task would occupy him for the rest of his working life, until 1454, when, ‘being so old and feeble that he is no longer equal to the task’, he was replaced by Gomes Eanes de Zurara.