From the Telegraph … I may have things to add later when I have time to look into this more detail:
In Roman mythology, the bough was a tree branch with golden leaves that enabled the Trojan hero Aeneas to travel through the underworld safely.
They discovered the remains while excavating religious sanctuary built in honour of the goddess Diana near an ancient volcanic lake in the Alban Hills, 20 miles south of Rome.
They believe the enclosure protected a huge Cypress or oak tree which was sacred to the Latins, a powerful tribe which ruled the region before the rise of the Roman Empire.
The tree was central to the myth of Aeneas, who was told by a spirit to pluck a branch bearing golden leaves to protect himself when he ventured into Hades to seek counsel from his dead father.
In a second, more historically credible legend, the Latins believed it symbolised the power of their priest-king.
Anyone who broke off a branch, even a fugitive slave, could then challenge the king in a fight to the death. If the king was killed in the battle, the challenger assumed his position as the tribe’s leader.
The discovery was made near the town of Nemi by a team led by Filippo Coarelli, a recently retired professor of archaeology at Perugia University.
After months of excavations in the volcanic soil, they unearthed the remains of a stone enclosure.
Shards of pottery surrounding the site date it to the mid to late Bronze Age, between the 12th and 13th centuries BC.
“We found many, many pottery pieces of a votive or ritual nature,” said Prof Coarelli. “The location also tells us that it must have been a sacred structure. We spent months excavating, during which we had to cut into enormous blocks of lava.”
The stone enclosure is in the middle of an area which contains the ruins of an immense sanctuary dedicated to Diana, the goddess of hunting, along with the remains of terracing, fountains, cisterns and a nymphaeum.
“It’s an intriguing discovery and adds evidence to the fact that this was an extraordinarily important sanctuary,” said Prof Christopher Smith, the head of the British School at Rome, an archaeological institute.
“We know that trees were grown in containers at temple sites. The Latins gathered here to worship right up until the founding of the Roman republic in 509BC.”
The story about the golden bough and Aeneas, who is said to have journeyed from Troy to Italy to found the city of Rome, was documented by Virgil in his epic, the Aeneid.
“Virgil tells us that the sibyls told Aeneas to go to the underworld to take advice from his father but he had to take a branch of gold as a sort of key to allow him access,” said Prof Smith.
The legend inspired JMW Turner to paint a grand canvas entitled ‘Lake Avernus – The Fates and the Golden Bough’, now held by the Tate Collection.
Addenda: There’s a bit more detail in the La Repubblica coverage: In questo vaso cresceva l’ albero con il ramo d’ oro. However, I’m curious on what basis they think this enclosure housed a tree. It’s certainly very interesting that this pushes the age of the sanctuary back to the Bronze Age …