The Arab conquests of the Middle East and much of North Africa and Central Asia in the seventh century mark the beginning of a process of religious and cultural change which ultimately resulted in the present Muslim-majority populations of almost all of these regions (see Figure 1.1). Yet the countries with the greatest Muslim populations today exist outside the Middle East in South Asia (India, Pakistan and Bangladesh) and in Southeast Asia, where Indonesia constitutes the largest Muslim-populated state in the world. Islam spread far into Africa and Europe too, and significant Muslim populations also arose in parts of the world which remained mostly non-Muslim, such as China and Ethiopia. This spread of Islam is often referred to as ‘Islamisation’, a term widespread in scholarship and in recent times in more popular media.