Exactly, try looking into the various crusades the islamicists launched into the west. They even took slaves from Ireland if you could imagine.
The turkishmuslims also used to go through christian vilalges taking strong young boys and converting them into muslims as a sort of "shock troop/elite force" known as Jannisaries.
They were the ones who took Byzantium.
The Muslims after taking The Iberian Peninsula got as far North as Tours, France where they were turned back in 1732 by the Army of Charles Martel. This marked the high water mark of Islamic conquests in Europe and brought about the end of the "Dark Ages".