The historical linkages between India and Southeast Asia date back to ancient times and represent one of the most significant examples of cultural interaction, trade expansion, and civilizational exchange in world history. These connections were not the result of political conquest in most cases, but rather developed through peaceful means such as trade, migration, religious propagation, and intellectual exchange. Over centuries, these interactions gave rise to a shared cultural sphere often referred to as “Greater India,” where Indian ideas and practices were adapted and integrated into local traditions across Southeast Asia. One of the earliest foundations of Indo–Southeast Asian relations was maritime trade. From around the early centuries of the Common Era, Indian traders began navigating the Indian Ocean and Bay of Bengal, establishing commercial links with regions such as present-day Myanmar, Thailand, Malaysia, Indonesia, Cambodia, and Vietnam. These traders were motivated by the demand for spices, precious woods, gold, and other exotic goods found in Southeast Asia. In return, Indian merchants brought textiles, beads, metalware, and other manufactured items. Ports such as Tamralipti, Arikamedu, and Kaveripattinam in India became important centers of overseas trade, connecting with Southeast Asian ports like Oc Eo, Srivijaya, and Funan. Alongside trade, the movement of people played a crucial role in strengthening these linkages. Indian merchants, artisans, priests, and scholars traveled to Southeast Asia and often settled there. This led to the formation of early Indian diaspora communities in the region. These communities acted as cultural intermediaries, facilitating the transfer of language, religion, art, and governance models. Unlike colonial diasporas, these early migrants integrated into local societies, often intermarrying and influencing local elites. Religious and cultural exchanges formed another major pillar of these linkages. Indian religions, particularly Hinduism and Buddhism, spread widely across Southeast Asia. Buddhism traveled through both land and maritime routes,