So wrote the opium-addicted 18th-century English poet Samuel Taylor Coleridge after a dream about the great Mongol ruler Kublai Khan.
A grandson of Genghis Khan, Kublai's realm stretched from the Pacific Ocean to the Black Sea, covering a fifth of the known world.
In 1279, he became the first non-Chinese emperor, establishing the Yuan Dynasty and ruling over China, present-day Mongolia, Korea and other Asian regions.
But his ambition to occupy more lands led to one of his worst defeats when he sent his warships to invade Vietnam in 1288.
Now, 725 years later, Australian archaeologists are helping excavate the site where the mighty Kublai Khan's invasion fleet of 400 was destroyed by the Vietnamese.
They had lured the Mongols up the Bach Dang River just as the tide was starting to ebb. The Vietnam army had driven hundreds of sharpened wooden stakes into the bed of the river that were invisible at high tide; when the tide turned and began to ebb, the entire fleet was holed and sunk, captured or burnt by fire arrows.
"The Bach Dang battlefield research project came about after Jun Kimura, one of my PhD students now at Murdoch University, was asked to go to Vietnam in 2008," says Dr Mark Staniforth, a senior researcher in archaeology at Monash University.
"I had been looking for an opportunity to do some research there on the site where Kublai Khan's fleet was defeated and went with him initially to help record a couple of wooden ship's anchors found in the Red River.
That gave me the chance to spend a few days in Bach Dang looking at the site and where we discovered the Vietnamese had been working since the 1950s.
They were doing a good job but suffered a few problems — mainly not having much in the way of equipment or money."