This chapter examines the rise of powerful kingdoms and maritime trading polities across the archipelago. It focuses on the economic and political ascendancy of Srivijaya, Majapahit, and other regional powers, fuelled by control over spice routes and tributary trade. It explores how Indianization and Islamization reshaped social structures and governance models, integrating local rulers into broader religious and commercial networks. The chapter demonstrates that control of trade flows, particularly in cloves, nutmeg, and sandalwood, enabled states to accumulate wealth and expand their administrative reach. However, internal fragmentation and shifting trade currents also produced cycles of rise and decline. These dynamics set the stage for European colonial intrusion.