How far into Europe did Muslim conquers get?

How was slavery in mesoamerica, africa, and the arab world similar? many enslaved people were forced to pledge loyalty to their owners. many enslaved people worked in exchange for protection from foreigners. many enslaved people were captured during war. many enslaved people taught and tutored children.

Two gymnastics teams are intense rivals. the first team has started recruiting new gymnasts from different cities and even foreign countires in an effort to build a stronger team. after learning this, the secondteam begins its own recruitment campaign to find better gymnasts. over a period of months, each team recruits dozens of players, each time trying to find a better recruit than its rivals most recent addition. which idea from the cold war is most similar to this scenario

Why is the sons of liberty a difficult group to describe ?