Over the past few months, the restoration of the monumental statue of Hercules Mastai involved several interventions that included:

• Cleaning of the surfaces
• Preparation of casts and resin copies of the nineteenth-century reconstructions
• Removal of the nineteenth-century gilded plaster fillings
• Selection of suitable mixtures for new structural and aesthetic reconstructions
• Refinement of mechanical and chemical cleaning of surfaces
• Casting of ankles, resin copies, and removal of historical plaster prototypes
• Cleaning of metal surfaces and rust conversion of iron elements
• Creation of a resin copy of the leaf and lower abdomen and gilding tests of the copies were made
• Removal of nineteenth-century stucco work on the face
• Selection of a mixture chemically inert to bronze, and stable over time, for making the new grouts
• Removal of nineteenth-century stucco work, detail at left gluteus

The creation of suitable surface protection is currently being studied.

The restoration project of the monumental statue in gilded bronze, the Hercules Mastai, of the Vatican Museums is an ongoing development. The chemical cleaning operations of the surfaces are on their way to completion. At the same time, restorers carry out mechanical cleaning operations to remove the cohesive concretions (probably silicates) on the entire surface of the gilding. These operations allow restorers to return the legibility to the original surfaces and identify the traces of bronze with greater ease.

The indications provided by the X-ray images defined the fractures of the bronze at the ankles, previously covered by nineteenth-century plaster reconstructions. Next, execution of the cast and copy will soon be made in a two-component acrylic resin. Restorers will reposition them with a reversible anchor system, an analogous design made for the cover and leaf. The 19th-century integrations will be removed and preserved in the storehouse. This occasion will make it possible to conduct a rust intervention on the pivots of the supporting structure and then proceed with the protection and chromatic agreement of the surface

August 8, 1864: a bronze finger emerges from the earth, and then a hand

August 31, 1864: at the depth of 8-9 meters - at 3.30 m. from the ancient level - the entire statue is brought to light, the works are conducted by the architect Luigi Gabet

"It was found on the occasion of certain excavations that the knight Righetti ordered in the courtyard of his palace, to lay the new foundations" (La Civiltà Cattolica. Anno XV, 1864, p. 731)

September 24, 1864: the statue is freed and suspended with a wooden scaffold

"I saw this statue resurrected from its tomb, raised using ropes, screws, and winches - all around commoners, workers, full of interest and cheerful gravity-a true Roman scene."

(F. Gregorovius, Diari romani 1852-1874, ed. 1992, p. 291)

October 1864: the statue is placed in a special room of the Palace and on October 6 it is inspected by Pietro Ercole Visconti and Pietro Tenerani.

January 9, 1865: Pius IX's visit formalizes the transfer to the Museums. Righetti receives 50,000 scudi and other gifts.

January 12, 1865: Pietro Ercole Visconti gives news of the discovery at the Pontifical Academy and proposes to call it the Mastai Ercole.

January 31, 1865: the statue is transferred to the Vatican, where it is restored by Tenerani.

April 1866: located in the Sala Rotonda

«… It is made of bronze with heavy gilding and is 3.83 meters high. It represents the young Hercules, who held in his right hand the club, of which several pieces have been found, and in his left hand the apples of the Hesperides, which are now missing; the skin of the lion has been found under the back of the statue, but its original place was on the left arm, from which it hung up to a little beyond the knee... The right arm hangs along the body, to which it is joined using a prop; nevertheless, according to the attitude of the hand, the club cannot have touched the ground but seems to be suspended in the air. The feet have detached from the legs: one of these, as well as the base of the statue, is still missing. There is the lack of the skull, that it seems almost cut for a crown to begin...There is a breakup of the bronze, a defect of the fusion, to the top of the head, together with the crown, it must have had another inserted piece..." (P.E. Visconti 1864)

The statue is similar to models of the first decades of the fourth century BC.

It was executed in Roman times, various chronologies were proposed:

• End of the first century AD. (Domitian restoration)
• Second half of the second century AD 
• Beginning of the third century AD (rest. Septimius Severus)
• End of the III century A.D. (rest. Diocletian/Massimian)