Abstract
Starting from the history of dynastic fratricide in the Islamic world and its institutionalization in the fifteenth century, we look at how in the Iberian area the distancing from the Islamic world has gradually become clearer. The cases of Abdallah I, Alfonso VI and Urraca, Berenguer Ramon II, in which dynastic fratricide is expected and accepted by custom in the first case, need to be denied with an oath in the second case, is subjected to divine judgment to condemn it, in the third case. The story of Pedro el Cruel goes beyond condemnation and shows punishment: the fratricidal king himself becomes the victim of his stepbrother. The final reference to Jacob Xalabín proposes a reading of the novel as a Christian condemnation of Islamic fratricide.