In the Treaty of Fontainebleau, the Allies exiled him to Elba, an island of 12,000 inhabitants in the Mediterranean, 20 km (12 mi) off the Tuscan coast. They gave him sovereignty over the island and allowed him to retain the title of Emperor. Napoleon attempted suicide with a pill he had carried after nearly being captured by the Russians during the retreat from Moscow. Its potency had weakened with age, however, and he survived to be exiled while his wife and son took refuge in Austria. In the first few months on Elba he created a small navy and army, developed the iron mines, and issued decrees on modern agricultural methods.
Is there an answer to this question (If it cannot be answered, say "unanswerable"): The allies permitted Napoleon to keep what title?
Emperor