[1]: 113 During the Napoleonic era, an unknown but immense quantity of art was acquired, destroyed, or lost through treaties, public auctions, and unsanctioned seizures.

Coins and objects made of precious metals, such as the Jewel of Vicenza and the bucentaur, the Venetian state barge, were melted down for easier sale and transport, to finance French military wages.

[3]: 30–31 With the intervention of abbot Henri Gregoire in 1794, the French revolutionary government moved to stop the vandalism and destruction of artworks by claiming them as a source of national heritage.

In many cases, this saved works of medieval or Gothic art from destruction, often through the intervention of experts like architect Alexandre Lenoir, abbot Nicolas Bergeat, and artist Louis Joseph Watteau.

[3]: 100,107  In November 1802, First Consul Napoleon Bonaparte appointed Vivant Denon director of the Louvre, the museums of Versailles, and the royal castle collections due to his successes in the Egyptian campaign.

[3]: 107,112  Denon, known as "Napoleon's eye",[7]: 33  continued to travel with French military expeditions to Italy, Germany, Austria, and Spain to select artworks for France.

[1]: 127 During and after their successful war against the First Coalition (1792–97), the French armies destroyed monuments, supported iconoclasm, and held art auctions of confiscated property in the Low Countries of northwestern Europe.

[6]: 26 The commission process set a pattern for the systematic appropriations to come,[11] and the French use of experts explains how they could select important Old Master artworks and discern them from copies and pieces made by artists' workshops.

[3]: 46,60  The first French exhibitions of the Low Country artworks took place in 1799, and included 56 works by Rubens, 18 by Rembrandt, Jan van Eyck's Ghent Altarpiece, and 12 portraits by Hans Holbein the Younger.

This glorious campaign, as well as allowing the Republic to offer peace to its enemies, should repair the devastating vandalisms by adding to the splendor of military victories the enchantment of consoling and beneficial art.

[21]: 133  Fewer works were taken from Sardinia (which was ruled by the House of Savoy from Turin at the time), although French attention turned to the documents, the codices of the Regal Archive, and Flemish paintings in the Galleria Sabauda.

[29] In Parma, after the 1803 orders and the creation of the French Taro department in 1808, more precious objects were stripped from the Ducal archaeological museum, such as Tabula Alimentaria Traianea and Lex Rubria de Gallia Cisalpina  [it].

[31] The Bucintoro, the Venetian state barge, was taken apart along with all its sculptures, much of which was then burned on the island of San Giorgio Maggiore to extract their gold leaf; the Arsenal of Venice was dismantled, and the most beautiful arms, armour, and firearms were sent to France, with the rest (including more than 5,000 cannons) being melted down.

[32][33] The weapons shipped to France were mostly placed in the collection of the Musée de l'Armée, including a bronze cannon made to celebrate an alliance between the Republic of Venice and Denmark–Norway.

[8]: 180  Swiss sculptor Heinrich Keller described the chaotic scene in Rome: The destruction here is awful; the most beautiful pictures are sold for a song [...] The holier the subject, the lower the price.

Through the summer and winter of 1811, after the Kingdom of Etruria had been annexed by the French Empire, Denon took artworks from dissolved churches and convents in Genoa, Massa, Carrara, Pisa, Volterra, and Florence.

[3]: 152 [38] In Florence, Denon searched the convent of Saint Catherine, the churches of Santa Maria Maddalena dei Pazzi and Santo Spirito, and the Accademia di Belle Arti di Firenze, and sent back works to the Louvre, such as Fra Filippo Lippi's Barbadori Altarpiece from Santo Spirito,[39] Cimabue's Maestà,[3]: 151  and Michelangelo's unfinished sculptures for the tomb of Pope Julius II were sent to the Louvre.[8]: 185 .

[16]: 438 The procession contained the Horses of Saint Mark, the Apollo Belvedere, the Venus de' Medici, the Discobolus, the Laocoön group, and sixty other works, among which were nine Raphaels, two Correggios, collections of antiques and minerals, exotic animals, and Vatican manuscripts.

[46] Following the Treaty of Lunéville between France and the Holy Roman Empire in 1801, manuscripts, codices, and paintings began to flow from northern and central Europe into Paris.

[3]: 117 With the Peace of Pressburg in December 1805 and the Battle of Jena–Auerstedt shortly after, Denon and his aides Count Daru and Stendhal began to systematically appropriate art from regions of the Holy Roman Empire, Westphalia, and Prussia.

After Napoleon's second abdication in June 1815, followed by another restoration of Louis XVIII, the return of art became a part of negotiations, although the lack of historical precedent made it a messy affair.

King Frederick William III of Prussia ordered diplomat von Ribbentropp, art expert Jacobi, and reserve officer Eberhardt de Groote to deal with the returns.

[53] French museum officials tried to hold onto any objects they had seized, arguing that keeping the artworks in France was a gesture of generosity towards their countries of origin and a tribute to their cultural or scientific importance.

[8]: 186 On 20 September 1815, Austria, the United Kingdom, and Prussia agreed that the remaining artworks should be returned, and affirmed that there was no principle of conquest that would permit France to retain its spoils.

[54] Russian Emperor Alexander I of Russia was not part of this agreement, and preferred to compromise with the French government,[16]: 451  having just acquired for the Hermitage Museum 38 artworks sold by descendants of Joséphine de Beauharnais to discharge her debts.

[55] After the Vienna agreement was completed, the occupying forces of Paris continued to remove and send artworks to Spain, the Netherlands, Belgium, Austria, and some Italian cities.

[16]: 455  Canova sent letters asking Wilhelm von Humboldt and Lord Castlereagh to support the return of Italian artworks and annul the conditions of the Treaty of Tolentino.

[8]: 186 For various reasons, including lack of money, knowledge of the theft, or appreciation for the value of the works taken,[8]: 186  the restored allied governments did not always pursue the return of the appropriated paintings.

[58] The Tuscan government, under the Hapsburg-Lorraines, did not request works such as the Saint Francis Receiving the Stigmata by Giotto, Maestà by Cimabue, or the Coronation of the Virgin by Fra Angelico.

From its opening in 1793, artists and scholars had flocked to the museum to see its expansive, exhaustive collections,[8] including Charles Lock Eastlake, Henry Fuseli, Benjamin West, Maria Cosway, and J. M. W.