Gibbon was educated at Magdalen College, Oxford, but thought little of it, as his Autobiography reveals. After a brief conversion to Catholicism at the age of sixteen, he was sent to Lausanne, where, under the tuition of a Calvinist pastor, he returned to Protestantism. There he frequented many intellectual salons, and came to know Voltaire. There, too, he became engaged to Suzanne Curchod, later to become wife to Jacques Necker and mother to Madame de Staël.
After he returned to England he began writing, beginning with his Essai sur l'étude de la littérature (1758). But his writing career was interrupted by a four-year stint in the Hampshire militia.
In 1764 Gibbon was in Rome, where he was struck with the idea for what became his greatest work, The Decline and Fall of the Roman Empire. The first volume appeared in 1776, and the series was finished in 1788. The famous chapters 15 and 16 attracted the most attention; in them he criticizes the institutions of early Christianity, and earned for himself the reputation of an atheist, which he hoped to combat in his Vindication of 1779. His Autobiography was published posthumously by his friend John Baker Holroyd, Lord Sheffield, along with other miscellaneous works, in 1796.