From the third century AD when the Hun invasion ended the Roman Empire, the Indian merchants relied more and more on the

1. The question describes a period starting from the third century AD when the Hun invasion contributed to the decline of the Roman Empire. 2. The decline of the Roman Empire significantly disrupted the established land and sea trade routes between India and the West (Roman world), which had been very prosperous. 3. Indian merchants, therefore, needed to rely more on alternative trade networks. 4. Southeast Asian trade had always been important, involving spices, textiles, precious woods, etc. With the decline of the Western trade, the relative importance of maritime trade with Southeast Asia (including regions like Suvarnabhumi/Suvarnadvipa - often identified with parts of Southeast Asia) increased. Indian cultural and commercial influence in Southeast Asia also grew significantly during and after this period. 5. While trade with Africa, the Middle East, and potentially indirectly with remnants of the Western world continued, the most significant reorientation or increased reliance for Indian merchants, particularly from southern and eastern India, was towards Southeast Asian trade. 6. West European trade was minimal during this period following the Roman decline. Middle Eastern trade remained important as an intermediary, but the focus shifted more towards the East.