Roman trade with India was initially undertaken through the overland caravan routes by way of Anatolia and Persia. It was at a relative drop comparative to later times, antedated the southern trade route passing through the Red Sea and Monsoons which began around the commencement of the Common Era (CE). This followed the reign of Augustus and his occupation of Egypt. The expansion of the Empires up to the upper Nile, the Romans logically came across the great warrior trading nation of Axum on the Red Sea, which had trade relations with India and Egypt for over several centuries.
Later on, usage of monsoon winds enabled a voyage safer in comparison of long and hazardous coastal voyage that was learned by the Romans from the Axumite Kingdom.