The Christian Reconquest started in 718, when Pelayo, a noble Visigoth, who was elected King, defeated the Muslim army In Alcama. But it wasn’t until 1492, with the marriage of Isabel I of Castile and Fernando II of Argon was the reconquest finalized with the expulsion of the Moriscos(Muslims) and the Marranos(Jews) in Spain.
In the interim of time between 718 and 1492, Jews, Muslims and Christians were able to live together maintaining what was called a covivencia or coexistence. (Shell 306). The Christians held the political power, the Jews controlled the learned professions and the Muslims dominated the engineering and architecture fields. They were able to work in unison in Spanish society by incorporating their difference in knowledge and religious difference into societal succession. But, 1492, after the marriage of Isabel and Fernando did that all change. They eliminated the Muslims as a political entity by conquering the Moorish kingdom of Granada and decreeded Christianity as the uniform religion throughout Spain. (Johnson, 6) The official view became that Christians with only Christians ancestors were Spanish nationals. This idea was introduced in Toledo in 1449 as the Statutes of the purity of the Blood, Limpieza De Sangre. Later reinforced in 1492. The statues enforced and emphasized the differences among the Christians, the conversos ( those who had converted from Islam or Judaism or whose ancestors did) contesting that those not born of pure blood were not true Spanish Nationals and therefore need to be expelled in order not to taint the Christian Spanish race. (The final consolidation of Spanish nationhood followed on the strict enforcement of the blood regulation under Philip II in the latter half of the sixteenth century) The Myth of pure blood (Sangre Pura) took hold. Blood unmixed with the Muslim blood or Jewish blood represented Honor and Purity where as Mixed blood was depicted dishonor and impure and considered a crime of the nation.
Because pure blood was essential, In order to rid of the impure blood and to solidify pure Christian blood, Jews were expelled from Spain and Muslims were expelled in 1502.

Work consulted

Shell, Marc. “Marranos (pigs), or From Coexistence to Toleration.” Critical Inquiry 17 ( winter 2002): 306- 335

Johnson, Carroll B. Don Quijote: The Quest for Modern Fiction Boston: Twayne,