In what ways were diverse people from the Arabian Peninsula through the Middle East, North Africa, and into Spain united? What held them together and unified them, and how was this done? The time zone was between 500 to 700 CE.

Answer 1

If your time period was between 700 and 900, then it would be the spread of Islam by conquering these lands.

http://www.yale.edu/yup/pdf/cim6.pdf

Answer 2

http://en.wikipedia.org/wiki/Moors