From the 8th till the 15th century Spain was controlled by Muslim forces (first all of Spain and later part of Spain).
Surprisingly, the occupation wasn't all bad for Europe, as the Arabs brought in a lot of the ancient texts from Greece. The English scholar, Adelard of Bath, for instance, went to Spain and translated the Elements, a great work of mathematics by the Greek mathematician Euclid.
Depicted is a battle from a European Spanish manuscript. Notice the European Christians held crosses and a flag witb Maria and child.
"The Great World History Book"