Gibbon was the son of established wealth and this afforded him opportunities for education and travel. On his grand tour of Europe, a young Gibbon was overcome by the grandeur and decay of Rome. He decided soon after that he would be the first modern historian to chronicle the history of the Roman Empire.
The arduous process of researching primary sources and writing consumed most of Gibbon's life as he catalogued the history of Rome from Emperor Marcus Aurelius (180 AD) to the Fall of Constantinople (1453 AD). When Gibbon published the first volume of his magnum opus in 1776 it was universally hailed as a success. The quality of his prose, his objective style and his use of primary sources became a model for future historians to emulate.
I will eventually finish all 1800 pages of the Decline and Fall however, following the GBWW program, I am only reading chapters XV-XVI at this time. These are two of the most controversial chapters in the entire series as they deal with the rise and incorporation of Christianity within the Roman Empire. Gibbon's description of early Christianity does not agree with the history promulgated by the Catholic Church and this discrepency was compounded by the fact that Gibbon relied on primary sources rather than later documents produced by the church.