600 m² of 16th-century Italian frescoes uncovered in Monaco's Prince's Palace

A vast cycle of Mannerist frescoes, covering 600 m², has been discovered in the Prince's Palace of Monaco. Painted in the 16th century by Italian artists, the frescoes feature the Labours of Hercules on the exterior and a rare Ulysses-themed interior, referencing Francesco Grimaldi's 1297 conquest of the fortress disguised as a monk. The palace, originally a fortress built in 1215, was transformed by Stefano Grimaldi in 1507, who commissioned Lombard architect Domenico Gallo. The frescoes show influences from Perin del Vaga and are attributed to a Genoese master and his workshop, similar to those in Palazzo Doria in Genoa. Restoration campaigns began in 2013-2015 with the Cour d'Honneur, followed by the Hercules Gallery, where missing sections were integrated with removable watercolor panels. In the Throne Room, a 1953 restoration was reversed; the ceiling depicts the Nekuia from Homer's Odyssey. A 1547 payment to Nicolosio Granello suggests his involvement, though no prior monumental frescoes by him are known. Eco-friendly methods, including laser cleaning by Italian firm El.en group, were used under Prince Albert II's directive. The 'Salon d'Europe' revealed a grotesque ceiling with the Rape of Europa, and a red-ground frieze was discovered. A scientific committee, including Pierre Curie of Musée Jacquemart-André, oversees restorations. The Green Antechamber and the Louis XIII Room are currently being restored, with the latter expected to open after 2024.