The Hundred Days (French: les Cent-Jours IPA: [le s u]), also known as the War of the Seventh Coalition, marked the period between Napoleon's return from eleven months of exile on the island of Elba to Paris on 20 March 1815 and the second restoration of King Louis XVIII on 8 July 1815 (a period of 110 days). This period saw the War of the Seventh Coalition, and includes the Waterloo Campaign, the Neapolitan War as well as several other minor campaigns. The phrase les Cent Jours (the hundred days) was first used by the prefect of Paris, Gaspard, comte de Chabrol, in his speech welcoming the king back to Paris on 8 July.Napoleon returned while the Congress of Vienna was sitting. On 13 March, seven days before Napoleon reached Paris, the powers at the Congress of Vienna declared him an outlaw, and on 25 March Austria, Prussia, Russia and the United Kingdom, the four Great Powers and key members of the Seventh Coalition, bound themselves to put 150,000 men each into the field to end his rule. This set the stage for the last conflict in the Napoleonic Wars, the defeat of Napoleon at the Battle of Waterloo, the second restoration of the French kingdom, and the permanent exile of Napoleon to the distant island of Saint Helena, where he died in May 1821.

Elba (Italian: isola d'Elba, pronounced [ˈiːzola ˈdelba]; Latin: Ilva; Ancient Greek: Αἰθαλία, Aithalia) is a Mediterranean island in Tuscany, Italy, 10 km (6.2 mi) from the coastal town of Piombino on the Italian mainland, and the largest island of the Tuscan Archipelago. It is also part of the Arcipelago Toscano National Park, and the third largest island in Italy, after Sicily and Sardinia. It is located in the Tyrrhenian Sea about 50 km (30 mi) east of the French island of Corsica.

The island is part of the province of Livorno and is divided into seven municipalities, with a total population of about 30,000 inhabitants which increases considerably during the summer. The municipalities are Portoferraio (which is also the island's principal town), Campo nell'Elba, Capoliveri, Marciana, Marciana Marina, Porto Azzurro, and Rio.

Elba was the site of Napoleon's first exile, from 1814 to 1815.