Short answers, pulled from the story.
Napoleon was exiled to Elba following his forced abdication under the Treaty of Fontainebleau in 1814. He was conveyed to the island aboard HMS Undaunted by Captain Thomas Ussher, arriving at Portoferraio on the 4th of May 1814. He was nominally sovereign of the island but permitted only a personal guard of 400 men.
Napoleon stayed on Elba for nearly ten months. He arrived on the 4th of May 1814 and escaped back to France on the 26th of February 1815 with about 1,000 men.
Elba is a Mediterranean island in Tuscany, Italy, located 10 kilometres from the coastal town of Piombino on the Italian mainland. It is the largest island of the Tuscan Archipelago and the third largest island in Italy, after Sicily and Sardinia. The island sits in the Tyrrhenian Sea about 50 kilometres east of the French island of Corsica.
Elba has been famous since antiquity for its rich iron ore deposits. The Greeks called it Aethalia, meaning smoky, after the fumes from its metal-producing furnaces. The mineral ilvaite was first identified on the island and takes its name from Ilva, Elba's Latin name.
Elba was liberated from German occupation on the 17th of June 1944 in Opération Brassard. French forces of the 1er Corps d'Armée carried out the operation, supported by British troops including Royal Naval Commandos. Faulty intelligence and strong German defences made the battle more difficult than expected.
The highest point on Elba is Mount Capanne, which rises to 1,018 metres (3,340 feet) above sea level. It is sometimes called the "roof of the Tuscan Archipelago" and is home to animal species including the mouflon and wild boar.