Elba is a small island in the sea west of Italy. In 1814, after Napoleon’s attack on Russia had failed and then his enemies in Europe had beaten him, they sent him there to live. Though actually it was not a prison cell: he still had people around him, but he was not free to leave the island. He did leave, in 1815, and came back to France for a short time before he lost again. After that they sent him much farther away, to Saint Helena. When history books say “Elba,” they almost always mean that first sending-away. It is a place name, so it takes a capital letter. People mention it as a story-point: a powerful man made small, for a while, on an island he could see Italy from.