Donatello’s bronze sculpture group depicting Judith and Holofernes (1457-1464) has returned to public display after 10 months of restoration. The sculpture was unveiled Monday at the Sala dei Gigli (Gallery of the Fleurs-de-Lis) in Florence’s Palazzo Vecchio, cleaned and restored using the latest technology.

Donatello took an original approach to the subject of the young Jewish heroine who saved her city by cutting off the head of the Assyrian general besieging it. He was the first to include the figure of Holofernes. The subject at this time was usually presented as just Judith holding the general’s decapitated head. Donatello captured the moment in dynamic action, Judith with her arm raised and sword in hand ready for the kill while Holofernes’ body is trapped between her legs, his limbs dangling off the edge of the statue’s base. Three Bacchic reliefs adorn the sides of the base.

The bronze was commissioned by Piero de’ Medici with the motif of Judith’s defeat of Holofernes standing as a model of freedom against tyranny for citizens to follow in defense of the Florentine Republic. After the Medici were expelled from Florence in 1495, the government of the new Republic confiscated the sculpture and moved it to the Palazzo della Signoria, the new seat of government. Piero’s original inscriptions on the plinth — one extolling Judith as a symbol of humility’s triumph over pride and virtue’s over lust, the other exhorting citizens to follow her example in defending the Florentine Republic — were removed and a new one installed marking the date of the confiscation/liberation of the bronze from the personal property of the ruler to the patrimony of Florence.

It was moved several times over the next centuries and it was out in the elements. By 1980, the bronze had suffered severe deterioration, so it was permanently moved to the Sala dei Gigli in Palazzo Vecchio. At the time of the move, the statue was given its first scientific restoration, but it was the 1980s and the techniques used then haven’t aged well. The bronze darkened over time and the protective coating turned out to be a literal dust magnet, having an electrostatic charge that attracts dust and an adhesive property the glues it to the surface.

The new restoration began with a painstaking examination and documentation of the bronze. The statue was dusted to expose as much of the surface as possible. That surface was then analyzed with new samples taken and compared to the ones collected 40 years ago.

After the diagnostic process was complete, conservators set to work addressing the problems that were identified.

The findings revealed a need for a more complex approach to renew the restorative effects of the previous work, whilst also removing the products of slow corrosion processes on the metal’s surface. The recent work has benefitted from improved understanding of the material, as well as new laser-based technology to treat the metal without the disadvantages of mechanical or chemical cleaning techniques used in the past. This work has also revealed localized areas of gilding on the bronze, which provides important information for how this statue (and others like it) can be more effectively protected in the future.