Posted Monday, July 31, 2006; 20:00 HKT

Exactly 20 years ago to the month, I left Cambridge with a small grant from the history department in my pocket, and set off to follow Marco Polo's route. I flew to Israel, and in Jerusalem acquired the same gift that Marco Polo took east with him: some oil from the site of Christ's resurrection. From there I headed through Cyprus, Syria, Turkey and the deserts of Iran, before crossing the mighty Hindu Kush and arriving at Kashgar in western China. I then took the southern Silk Road, looping between the Gobi Desert and the Himalayan foothills of Tibet, before heading eastward to Beijing, then still a city of bicycles and Mao suits. The final leg of my journey took me up into Inner Mongolia to Shangdu, Coleridge's Xanadu, where I poured the holy oil on Kublai Khan's throne dais. The journey took nearly four months and cost me only £750—exactly the grant that my college had given me.

Much has changed since then, both in my life and the world I traveled through. The account of that journey that I wrote on my return, In Xanadu: A Quest, was a lucky best seller, and started me on my career as a travel writer and historian. Since then, five more books have followed. None of this would have been possible without that initial kick start from Marco Polo. He is a figure I still look on with great affection; after all, he gave me my first job.

The changes that have taken place in the world have, of course, been even more dramatic and unexpected. Only recently has the West really woken up to the rise of the East. Futurologists now all agree that China and India will come to dominate the global economy some time in this century. Remarkable as this may seem to us, it is not a scenario that would have surprised Marco Polo in the least. What is perhaps most striking is how the world is now more like it was at the time of Marco Polo than it was 20 years ago. In his day, Europe was merely a primitive promontory on the edge of Asia, which then—as is increasingly the case today—was the world's economic powerhouse and principal manufacturing center.

Marco Polo is often thought of as an adventurer, but the truth is that he was first and foremost a hard-nosed businessman who went East not as tourist but economic migrant. His much misunderstood book was not some sort of 13th century Lonely Planet guide. For all the romantic top spin given it by his Genoese ghost writer Rustichello, Polo's book was simply meant to be a straightforward merchant's manual on the commerce of the Silk Road. Moreover, there is nothing at all surprising about Marco Polo reaching China. In the 13th century, the Mongol empire stretched from modern-day Poland to the Pacific. It had excellent communications—infinitely more sophisticated than those of medieval Europe—and Polo was one of a great number of Europeans who took advantage of the opportunities this presented.

The world economy that these merchants inhabited shattered a century or so later, in the revolution of global trade that took place following Portuguese explorer Vasco da Gama's discovery in 1498 of the sea route to the East. Bypassing the Middle East, and conquering the centers of spice production in South Asia, European colonial traders—first the Portuguese, then the Dutch and finally the British—wrecked the old trading network and imposed with their cannons and caravels a Western imperial system of command economics. Looked at now with hindsight, what is happening today with the rise of India and China is merely the rebalancing of the traditional equilibrium, with Europeans not as colonial masters but instead reverting to their old role as consumers of the goods and services of the East.

One other thing, less comforting, is the way the politics of Polo's trip have likewise reverted to those of the 13th century. Marco Polo was also carrying out a secret diplomatic mission for the Pope. In the Middle East, the forces of Arab Islam under Sultan Baibars, the leader of the mamluks in Egypt, were launching a bloody and largely successful counterattack against the Crusaders—whom the Arabs saw as an example of Christian imperialism. The Pope sent Polo and his father and uncle to try and convert the Mongol emperor to Christianity, and so find an ally beyond the Islamic world.

Today we find East and West and Islam and Christianity again facing each other uneasily across a divide that many see as a religious war, and again the West is seeking allies in South and East Asia against its enemies in the Middle East. Then, as now, the histories of Islamic fundamentalism and European imperialism have very often been closely, and dangerously, intertwined. It is easy to blame one side. But it should always be remembered that in a curious but very concrete way, the fundamentalists of both faiths have needed each other to reinforce each other's prejudices and hatreds. Then, as now, the venom of one provides the lifeblood of the other.

William Dalrymple's latest book, The Last Mughal: The Fall of a Dynasty, Delhi 1857, will be published in October