The year 2006 represents a great Jubilee of sorts for art historians. This Saturday marks the 500th anniversary of the rediscovery of the Laocoon group, one of the most renowned sculptures of the ancient world.

Virgil immortalized Laocoon in the "Aeneid." The Trojan priest of Neptune, Laocoon, when faced with the great wooden horse left by the Greeks outside the walls of Troy, issued one of the most famous warnings in the history of literature. "Men of Troy, trust not the horse! Whatever it be, I fear the Greeks, even when bringing gifts," later shortened to the popular dictum: Beware of Greeks bearing gifts.

Laocoon paid dearly for his acumen. As he performed the ritual sacrifice at the altars accompanied by his two young sons, a pair of huge sea serpents "with blazing eyes suffused with blood and fire" rose out of the water and attacked the family. Before the eyes of the horrified Trojans, they all died as Laocoon "strains his hands to burst the knots" and "lifts to heaven hideous cries."

His sculptural representation, as well as his literary personage, amassed great fame. Pliny the Elder, Roman statesman and scholar, wrote about the work in Book XXXVI of the "Natural Histories." He described a statue of Laocoon from the first century A.D., carved by three Greek sculptors, Hagesander, Polydorus and Athenodorus, in the house of Titus in Rome. He lauded the work as "superior to any painting and any bronze."

Renaissance artists were familiar with Pliny's book and knew the names and descriptions of some of the most important works of the ancient world. The statue itself had been lost long centuries past and only Pliny's encomium kept its memory alive.

Until 1506. Francesco da Sangallo, son of Michelangelo's close friend Giuliano da Sangallo, was eyewitness to the events of Jan. 14. Francesco recounts that Pope Julius II sent his father to look over some recently unearthed statues and "since Michelangelo Buonarroti was always to be found at our house, my father wanted him to come along, too."

When they arrived at the hole in the ground where the work lay semi-buried in leaves, roots and dirt, Giuliano exclaimed, "That is the Laocoon, which Pliny mentions."

Hailed throughout Europe as the most exciting find of the era, the statue attracted many potential buyers. Pope Julius succeeded in purchasing the work and then made an unusual but momentous decision. Instead of bestowing the work on his own family, the Della Rovere, he gave Laocoon to the Vatican so as to enrich the patrimony of the Church. For most of 500 years now, it has graced the octagonal courtyard of the Vatican Museums.

For Michelangelo, the rediscovery of Laocoon was earth-shattering. Fresh from his groundbreaking work on the "Pietà" and the "David," the 31-year-old Florentine sculptor was in Rome for the most promising commission of his career. He was to build a tomb for Julius II: a free-standing, three-story monument, covered with 40 sculptures by Michelangelo's hand.

Michelangelo, sculptural prodigy, was profoundly moved by the sight of Laocoon. He called it "a singular miracle of art in which we should grasp the divine genius of the craftsman rather than try to make an imitation of it."

Although he would never complete the papal tomb, Michelangelo used that revolutionary triumph of sculpture as inspiration for his greatest painting, the vault of the Sistine Chapel, begun two years after the finding of Laocoon.

Close observers can see the form of Laocoon represented several times in the ceiling, seen from different perspectives. One more reminder of the Greeks' deep impact on Rome.