This article explores one of the remarkable legacies of the Hellenistic Greek world: the subsequent activity in the Indian Ocean of Greek-speaking Egyptians and certain people of India who called themselves Yavanas. But while doing so, it addresses certain vexing issues. One is whether merchants from Roman Egypt established stable residential communities in the ports of India during the first and second centuries AD. Another is how Yavanas living near the Gulf of Barygaza and the western Ghats in western India came to call themselves by a term borne centuries earlier by Greeks living in regions of northern India. By probing these issues, the article sheds light on how travellers and expatriates from Roman Egypt, and the Greek language and culture that they often carried with them, fit into the multilingual and multicultural web of a connected Indian Ocean. But it also formulates how a commercial network of Egyptians established residential settlements in the ports of India that generated and transmitted local knowledge to other members of the network. The author of the notable Periplus of the Erythraean Sea (Periplus Maris Erythraei) was arguably both a participant in the network and a recipient of its knowledge.