Final answer:
Adopting Islam benefited Southeast Asian rulers by integrating them into prosperous Islamic trade networks, bringing regional stability, and fostering the exchange of ideas. This helped to unify their populations, legitimize their rule, and increase their wealth and power.
Step-by-step explanation:
Adopting Islam as a religion proved beneficial for Southeast Asian rulers for several reasons. During the 13th century, the spread of Islam into Southeast Asia facilitated the participation of these regions in the extensive and prosperous Islamic trade networks. Merchants who converted to Islam were able to ensure the safe movement of their goods and protection under Islamic law. This inclusion into a larger network also allowed local rulers to access new ideas, technologies, and established trade routes with Islamic merchants who traveled from India, Persia, Arabia to Africa.
Sufi missionaries, who blended Islamic teaching with local traditions, encouraged non-merchants to convert, thus integrating diverse communities under Islam within the region. This helped Southeast Asian rulers because it unified their populations under a single religious framework, which in turn likely strengthened their hold on power and legitimized their rule.
Furthermore, Islam brought stability to the region, fostering an environment where trade, learning, and the exchange of ideas flourished. This increased wealth and power for the ruling classes. Thus, Southeast Asian rulers adopted Islam partly to tap into a wider economic network and to align themselves with the prevailing sophisticated and prestigious political and cultural institutions associated with Islamic civilizations at the time.