On April 9, 1609, a decree was issued ruling that all descendents of Spanish Muslims, known as “Moriscos” or “new Moorish Christians,” were to be expelled. The final decision of 1609 was a political decision dictated by many political circumstances. The decision could have been avoided, taken at another time or postponed indefinitely. However, once expulsion had been decreed, royalty found the need to justify the measure before the public and did so to clarify two conflictive aspects: on the one hand, this was the first time that an officially baptised collective was expelled; and on the other, expulsion affected the whole group and not individual subjects. These two measures—unprecedented in the western Christian world—required a discourse to explain the “justification” for a measure that, in theory, breached Roman and Christian Law, creating a dangerous precedent. This paper examines these different discourse strategies and the historiographic narratives that tried to define common characteristics of the Morisco community, give it certain unifying features and make it a “hateful” archetype that had to be eliminated once and for all.