Edward Gibbon developed a great passion for reading in his childhood. The delicate state of his health meant that the young Edward received an unconventional education (from his father and private tutors). A sudden improvement in his health at the age of fifteen induced his father to enroll him at Magdalen College in Oxford. His studies of Christianity and the Christian world led him to question his Protestant faith and in June 1753 he was converted to Roman Catholicism, a move that resulted in his expulsion from the college (at that time Oxford University was open only to Anglicans). This turbulent phase was followed by a journey to Lausanne, which Gibbon's father forced him to take in order to bring him back into the Protestant fold under the guidance of a Calvinist pastor. It was here, at Christmas 1754, that he was reconciled with Protestantism. He stayed in Switzerland for five years, expanding and enriching his classical education through study of logic and Greek, and made the acquaintance of Voltaire. On his return to England in 1758, he embarked on the phase of his life devoted to scholarship and writing. In 1761 he published his first book, written in French and entitled Essai sur l'étude de la littérature. After serving for two years in the Hampshire militia, he set off for Europe again. It was in 1764, when his European tour had taken him to Rome, that he was inspired to write the Decline and Fall of the Roman Empire, by the vestiges of antiquity he saw in the city. A work in three volumes, it was published between 1776 and 1788 and covered the history of Europe from Augustus to the fall of Constantinople. He also wrote Gibbon's Journey from Geneva to Rome (1764).