TIVOLI, Italy (Reuters) -- A temple built by the Roman emperor Hadrian to honour the death of his young male lover and lost to the world for almost 2,000 years has unexpectedly come to light.

The ruins of the enormous semi-circular structure were uncovered during new excavations at Hadrian's sprawling villa about 30 km (18.6 miles) east of Rome.

It provides fresh insight into one of the world's most famous homosexual relationships.

"It's been something of a soap opera with lots of unexpected twists and turns," said Anna Maria Reggiani, the superintendent of archaeology for the Lazio region.

"No one knew what to expect, but now we are convinced that we have found the missing monument to Antinous," she added.

"This is the most important archaeological discovery in this region for years."

Hadrian lived from 76-138 AD and was regarded as one of Rome's finest emperors.

He was said to have been grief stricken when his teenage Greek lover Antinous drowned in the Nile in 130 AD.

It is not known if Antinous fell into the water, committed suicide or was pushed in, but Hadrian immediately declared him a god and founded the memorial city of Antinopolis in Egypt on the spot where the boy's body was found.

But until now, it appeared that Hadrian had never built a temple to his court favourite at the villa that served as his government headquarters and luxurious personal residence.

Peace and prosperity Statues made in the image of Antinous to honour the new deity were erected throughout the Roman empire after his death, providing a kind of photographic record of the beautiful teen.

Hadrian ensured relative peace and prosperity for the Roman empire during his reign from 117 AD to 138 AD.

His villa was abandoned when he died and later pillaged during the Renaissance to build the neighbouring gardens and Villa d'Este.

Zaccaria Mari, the head archaeologist on the site, started to dig outside the main villa complex in 2000 on a hunch that he would find a new gateway into the complex.

He uncovered a piazza marking the main entrance to the villa coming from Rome and the original rectangular flagstone driveway that leads to carriage "garages," but he also made what is being called the most important recent discovery in the region.

Archaeologists have dug up parts of the walls of the monumental temple that dates to 134 AD, shortly after Antinous' death, and made a couple of exploratory excavations.

"We found a series of fountains and planters for interior gardens, niches for statues and very important marble fragments, some with Egyptian hieroglyphics," Mari said.

Egyptian art is believed to represent Antinous since he was declared a god, Osiris-Antinous the Holy, on Egyptian soil.

"I'm sure this discovery will cause a lot of controversy, because it flies in the face of previously accepted theories, but only further excavations will give all of the answers," said Reggiani.

New Antinopolis

The Temple of Antinous