There was a "golden age" of the Moors in Spain, yes, but it didn't last. By the 11th century, the Almoravids and the Almohads had destroyed it, and the Jews and Christians were forced to convert or emigrate.

The Spanish and the Portuguese were particularly violent conquerors, yes, but they also were reacting to the previous Moorish conquest. It was a time of conquests back and forth, with civilisations basing their identities on religion, a bad idea that transformed ordinary conquest into religious wars.

The overseas colonial conquests started...The Christians killed more because they had access to more overseas territory,if the Muslims had gotten there first, it would probably have been them.

The new movie Silence depicts another religious conflict, this time the Japanese reaction to Christian missionaries, and that turned bloody too. The Japanese were not welcoming of new religions...