The Roman philosopher Pliny the Elder has credited the first century BC Greek navigator Hippalus for discovering the monsoon winds. It is believed that Hippalus was the first to discover that the monsoon winds could be used to make a voyage from the Red Sea to India. But Indian sailors and traders had been using the monsoon winds to reach Red Sea ports for centuries before Hippalus. In the time of Alexander, sea trade was flourishing between India and Egypt. The Greek historian, Strabo, has claimed that hundreds of ships laden with goods from India used to arrive in the Red Sea port of Myos Hormos.
From the time of the Persian Empire, Indians and Europeans were using land routes to communicate and trade. The land routes went through the passes located in modern day Pakistan and Afghanistan: the Khyber and Kurrum passes. Another route went through the Makran Coast (in southeastern Iran and southwestern Pakistan). Most of these regions were under Hindu and Buddhist kings in the ancient period; Iran was under Persian kings.
In 634 AD, the Arabs conquered Baghdad; they conquered Syria in 636 AD; Persia between 633 to 654 AD; the holy city of Jerusalem between 636 and 637 AD; and Egypt between 639 and 646 AD. After conquering Carthage on the Northern African coast in 698 AD, the Arabs set their eyes on Europe. In 711 AD, they crossed the Gulf of Gibraltar and conquered the Iberian Peninsula (much of modern Spain and Portugal). In 1453, the Ottoman armies conquered the last bastion of Christianity in the Middle East: Constantinople. With the fall of Constantinople, the Islamization of the Middle East and North Africa was complete.
Due to the Islamic conquests of North Africa, the Middle East, and the Iberian Peninsula, for more than 700 years, between the seventh and the fifteenth centuries, the direct land and sea link between India and Europe was broken. Indians and the Europeans could communicate and trade only through Arab intermediaries. The knowledge of India was transmitted to Europe through the Arabs—this included the knowledge of Hindu numerals, Vedic philosophy, medicine, moral theory, military science, and games like chess.
The traders of Europe became dependent on the Arabs for procuring goods from India and other eastern kingdoms. The Arabs were now in a position to demand a massive premium on the Eastern goods going to Europe. The European traders had no option except to pay whatever the Arabs demanded, since they had no way of developing direct connections with the producers of the East. The high price of Eastern goods—particularly textiles and spices, which could be procured only from India—had a detrimental impact on the economy of the European states.
The conflict between Christianity and Islam was not confined to the conquest of territories and exercise of economic power—a big thrust was on winning converts to their own religion. Having lost millions of followers and many of their holy sites to Islam in the Middle East and North Africa, the Christians were desperate to expand and replenish their numbers. They took aggressive steps to gain converts in Europe and Russia. The Orthodox Christianity of the Byzantine Empire found converts in Eastern Europe and Russia. A series of crusades and other campaigns were orchestrated by Rome’s Catholic Christian establishment to convert Western Europe.
In the second half of the fifteenth century, after wresting control of Spain and Portugal, the Christian monarchs turned their attention to the mission of discovering a sea route to India that would bypass the Islamic strongholds of the Middle East and North Africa. The Portuguese sailor Vasco da Gama was the first European to find a new sea route to India. Sailing from Lisbon, and going around the Cape of Good Hope, his four ships reached India on 8 July 1497. After a break of more than 700 years, a direct link between Europe and India was once again established.