The historical development that explains the role of Islam in the countries listed in the table is the spread of Islam through conquest and trade in the centuries following the death of the Prophet Muhammad. As Arab armies conquered new territories in the Middle East, North Africa, and beyond, they brought Islam with them, and many people converted to the new religion. Later, Muslim merchants and scholars spread Islam through trade and education, and Islamic ideas and practices became established in many parts of the world. This historical process helps explain why so many of the countries in the table have large Muslim populations and why Islam is such an important cultural and political force in those countries.