The celebrated sculpture of Laocoön and his Sons was unearthed in a vineyard near the Colosseum on January 16th, 1506. The vineyard was the property of Felice de Fredis, who sold the work to Pope Julius II (r. 1503-13). The Pope had it put on display in the Octagonal Courtyard (then known as the Cortile delle Statue), where it has been ever since (apart from a brief sojourn in Paris between 1798 and 1816).
In Virgil's book The Aeneid, Laocoön was a Trojan priest, who was killed, with both of his sons, after attempting to expose the Greeks' ruse of the wooden horse. Laocoön struck the horse with his spear, warning his fellow Trojans not to accept it: "Timeo Danaos et dona ferentes". (I fear the Danaans [Greeks], even those bearing gifts.)
In his Naturalis Historia, Gaius Plinius Secundus (23-79), better known as Pliny the Elder, refers to the statuary group of the Laocoön, which then stood in the palace of the emperor Titus and bore the names of three sculptors from Rhodes: Hagesandros, Athenadorus and Polydoros.
When the statue was unearthed, Laocoön's right arm was missing, along with part of the hand of one of his sons and the right arm of the other, and various sections of snake. Before the sculpture was put on display, all the missing parts were replaced, as was the practise of the time.
Four hundred years later, in 1906, Ludwig Pollak, an Austro-Czech archaeologist, antiques dealer and director of Rome's Museo Barracco, made a remarkable discovery. While rummaging about in a builder‘s yard, close to where the sculpture had been found, he came across a fragment of a marble arm, which bore a stylistic similarity to the figure of Laocoön.
He presented it to the Vatican Museums, where it remained in their storerooms for half a century. It wasn't until 1957 that the faux limbs were finally removed and Pollak's fragment reattached.