Short answers, pulled from the story.
Emmanuel comte de Las Cases was born on the 21st of June 1766 at the castle of Las Cases near Revel in Languedoc. He received his education at the military schools of Vendôme and Paris before entering the navy.
Emmanuel comte de Las Cases published the original edition of his famous atlas in English under the pseudonym A. Lesage in 1801. This publication immediately proved a great success among buyers and later made him rich enough to change his entire life trajectory.
Emmanuel comte de Las Cases accompanied Napoleon to Saint Helena because he first proposed and strongly urged the emperor to throw himself on the generosity of the British nation. He then acted as secretary taking down numerous notes that formed the basis of the Mémorial de Sainte-Hélène.
Emmanuel comte de Las Cases died on the 15th of May 1842 at age 75 in Passy where he is buried in Passy Cemetery. His death occurred shortly after his son traveled to St Helena to retrieve Napoleon's remains in 1840 while Las Cases was too ill to go.