A farmer tending a cotton field in central Greece has uncovered a stone monument marking the spot where the Roman army stopped a major westward offensive more than 2,000 years ago, a Greek archaeological official said Wednesday.

"This is the location of one of the biggest battles in Greek history ... where a huge army from the east was assembled against Rome," the official, Vassilis Aravantinos, said.

The site near Orchomenos, about 75 miles northwest of Athens (search), was recorded by the Greek historian Plutarch. But the actual location of the long-sought monument — originally believed to stand 23 feet — was a mystery until last month, when the farmer plowing his fields stumbled upon a buried column that led researchers to uncover the monument's stone base.

Another Roman victory monument (search), at nearby Chaeronea, was found in 1990 by students from the University of California, Berkeley.

The 86 B.C. battles at Chaeronea and Orchomenos inflicted a heavy defeat on Mithridates VI, who led the Black Sea kingdom of Pontus in an unsuccessful 20-year campaign against Rome.

The monument was raised by a Roman general, Lucius Cornelius Sulla (search), who defeated the Asian forces.

"Sulla's forces of 15,000 — I think it is not an exaggeration — faced the massive armies of the King of Pontus Mithridates, whose forces exceeded 100,000," Aravantinos said.

"It's one of these rare times when the ancient texts meet archaeology. For Rome, this battle meant salvation, and for Greece the effect was great because Sulla brutally punished the Greek towns that sided with his enemy."

The column was styled to look like a tree trunk bearing the armor of fallen soldiers from the defeated army, a common style at the time, a culture ministry statement said.

Aravantinos said the farmer who found the column delivered the remains of the column to the entrance of the archaeological institute using an earth-moving machine while the facility was closed. The farmer left no information about himself or where the column had come from.

But "this was too big to keep a secret," said Panayiotis Kravaritis, an institute official who helped find the spot where the monument once stood. "Eventually we found the farm, and the farmer led us to the spot where the monument is."