In the article, I try to show the world of the past as the world of games. First of all, history appears as a game – the game of the historian with his subject of study or cognition. Secondly, history itself can be conceptualised by the metaphor of the game. The history of Portugal is treated as an example of the object of historical research, which changes along with the theories applied. The act of theorising sets the limits of the known past. On the basis of selected examples from the history of Portugal in the 20th century, I try to show how the use of various research tools allows us to ask new/different questions.