Reconquista
The Reconquista (Spanish and Portuguese for "reconquest") was the Christian reconquest of the Muslim parts of the Iberian Peninsula, from 711 to 1491. There are various associations with the Crusades,
In politically correct descriptions, the Muslim areas (Al-Andalus) are now frequently described as a multicultural utopia. See the Al-Andalus article regarding this.
Another related topic with less politically correct aspects is the Spanish Inquisition.