The Portuguese representations of the sieges of Diu have been produced over the span of five centuries.My main argument is that, in these texts, Diu served as a pretext to reaffirm the glories of Portugal in Asia during the 16th century, as well as to establish an ontological and epistemological distinction between the West and the East. Such representations stem from what Eduardo Lourenço calls 'Portuguese hyperidentity', a notion which helps us understand how the discourses about Diu articulate knowledge and power. The relevance of establishing a connection between Edward W. Said's theory of Orientalism and Lourenço's viewpoint lies in the fact that both the 'Western conceptions of the Orient' and the affirmation of Portuguese identity and belonging participate of what Michel Foucault called 'regime of truth'.