Answer:
Islam spread through military conquest, trade, pilgrimage, and missionaries. Arab Muslim forces conquered vast territories and built imperial structures over time.
Step-by-step explanation:
How it began:
Islam came to the Southeast Asia, first by the way of Muslim traders along the main trade-route between Asia and the Far East, then was further spread by Sufi orders and finally consolidated by the expansion of the territories of converted rulers and their communities.
Where did they expand:
Islam was the religion of all of Arabia. By 732, the Islamic empire stretched from the borders of India, through Persia and the Middle East, along the north coast of Africa, and into Spain.