The apex of Enlightenment history was reached with Edward Gibbon's monumental six-volume work, "The History of the Decline and Fall of the Roman Empire", published on 17 February 1776. Because of its relative objectivity and heavy use of primary sources, its methodology became a model for later historians. This has led to Gibbon being called the first "modern historian". The book sold impressively, earning its author a total of about £9000. Biographer Leslie Stephen wrote that thereafter, "His fame was as rapid as it has been lasting."