A comparative study of the Siete infantes de Lara as it has been preserved in the Version primitiva and the Version critica of King Alfonso X's Estoria de Espana reveals a series of deliberate, systematic modifications made to the later rendering of the legend. In the Version critica , King Alfonso and his chroniclers vilify the character of Ruy Velazquez to a greater degree, putting into sharp relief the dangers such covert enemies posed to the security of Castilla. They also deglamorized the Moorish characters and suppressed those details suggesting that the Castilian nobles enjoyed personal and/or political ties with their southern neighbors. When considered alongside other texts produced under the Wise King's auspices, this chronistic rewriting sheds light on how the monarch hoped to use heroic tales like the Siete infantes as a means to achieve his political and didactic objectives.