His end didn't begin heroically. The Mongolian ruler simply fell off his horse. His hands and legs must have lost their strength. It was an embarrassing incident from which Genghis Khan never recovered.

Shortly thereafter, a procession of slaves and warriors escorted the ruler's body, wrapped in a white felt blanket, to its final resting place. Slivers of fragrant sandalwood were placed in the grave to prevent insects from gnawing at the body of the Great Khan.

But where exactly did the subjects bury the body of this tyrant, who is still revered by Mongolians today? Over the past century, scores of adventurers and archaeologists have searched in vain for Genghis Khan's grave.

Today, expeditions with high-tech equipment are racing to make the find. Not surprisingly, Mongolians claim their national hero's grave is located within the borders of their own country. A Russian historian, though, claims to have discerned from old sources that the nomadic leader was buried near the Mongolian border -- but on the Russian side, in the Republic of Tuva....