In the Song of Roland, the association of Roland, the valiant (‘proz'), with Oliver, the wise (‘sages'), forms a duo of apparent opposites. The main characteristic of one seems to exclude that of the other, although we probably should not reduce the depiction to such drastic polarisation. Two centuries later, the character of Alexander in his eponymous Libro de Alexandre chooses to surround himself in battle with mature men, recognised for their wisdom, instead of young soldiers: the reason being that the youngsters tend to escape rather than fight for victory. Here are two episodes, selected amongst others, which lead us to question the meaning of heroism and wisdom, two notions often perceived as mutually exclusive. Is it possible for the wise man to be characterised by his heroism, and vice versa? Does a certain type of heroism particular to the wise man exist?