It all stemmed from a photograph in an old dusty book. The scene was of towering mountains enveloping a verdant river valley, through which Alexander the Great apparently passed 2,300 years ago. Like the photographer, the explorer Sir Aurel Stein, I too wished to wander in the depths of Asia in search of clues to the ancient past.

For more than two thousand years Alexander the Great has excited the imagination of people around the globe. I became fascinated by Alexander some 18 years ago when a history teacher at school unravelled a map of the classical world and traced the outline of his journey with his finger. Who could not be intrigued by a man who inspired his soldiers to march for 12 years, beyond the known ends of the earth. They tramped some 22,000 miles; from Greece all the way to India and back to Babylon. By the time the Macedonian king died at the age of thirty two in 323 BC much of the known world lay beneath his feet.

Having studied his campaign in libraries I wanted to get out on the ground and see how the landscape with its mountains, rivers, and deserts shaped his strategies and determined his route. Geography so often governs history, and I wanted to see it up close for myself. I decided to organise an expedition focusing on Turkey, ancient Asia Minor, retracing his footsteps from the enigmatic city of Troy to the site of the Battle of Issus. What better way than to walk the 2,000 miles, travelling at the marching speed of his army and experience something of the physical rigours he faced. I wanted to behold the monumental ruins of cities he visited or attacked, and to search for ancient roads, upon which his soldiers trekked. It took Alexander and his 40,000 soldiers eighteen months to reach Issus. I would refrain from fighting battles, besieging towns, and the occasional spot of pillaging, and so hoped to complete the route in some twenty weeks, covering about fifteen miles a day.

Turkey is a veritable treasure trove for those enthralled by Alexander. First stop should be Istanbul