What is meant by national referendum ?

The name and use of the 'referendum' is thought to have originated in the Swiss canton of Graubünden as early as the 16th century. ... In contrast, Ireland has only ever held one plebiscite, which was the vote to adopt its constitution, and every other vote has been called a referendum.
Does that help I’m not sure?

On april 20, 1814, the dethroned emperor left france for the isle of  elba, where he was exiled under the terms of the treaty of fontainebleau.napoleon  would be allowed to ruleelba, which had 12,000 inhabitants. perhaps cruelly, the treaty allowed him to retain the title "emperor."