Historical interpretation of Portuguese Overseas Expansion has changed considerably from the late nineteenth century to the present. Ideological appropriations of historical events are commonplace. The propaganda of the regime of Portuguese dictator Antonio de Oliveira Salazar extensively used the topic of Portuguese Overseas Expansion as a founding myth for justifying its own colonialism, even in times when decolonization processes were the common trend. Damnatio memoriae, on the one hand, and apologetics, on the other, were strategies spread from primary school textbooks to university programmes. They were responsible for the exclusion and even persecution of many Portuguese scholars, who had to ask for refuge in other European Universities. It created myths, for example around Henry the Navigator or the Nautical School of Sagres. Key-personalities, such as Magellan, were long defamed as anti-heroes. This article will show how these myths and twisted interpretations are still commonplace today. Even now, many Portuguese feel that, in times of crises, these fictions are used to create a sense of national identity and self-confidence.