How were Islam and Muslim civilization able to spread across such a vast area spanning several continents with existing religious traditions and cultures?

Through the conquering of other territories and the treatment of conquered people and also the establishment of new trade routes and posts wherever they spread--religion was able to spread.

Explanation:

Islamic religion kept expanding and conquering neighboring territories-making Arab tribes convert and Abu Baker was able to unite Muslims. Ended warfare between Arab ad united under one leader. Kept moving forward and conquered Persians because of their weakened forces and conquered great parts of the Byzantine Empire.

b) the importance and limits of political power.

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