Gulliver's Travels is a novel by Jonathan Swift that is both a satire on human nature and a parody of the "travellers' tales" literary sub-genre. It is Swift's best known and most esteemed work, and a classic of English literature. The book begins with a short preamble in which Gulliver, in the style of books of the time, gives a brief outline of his life and history prior to his voyages. He enjoys travelling. This turns out to be fortunate. The book proper then is divided into four parts, which are as follows: Part I: A Voyage To Lilliput Part II: A Voyage to Brobdingnag Part III: A Voyage to Laputa, Balnibarbi, Glubbdubdrib, Luggnagg and Japan Part IV: A Voyage to the Country of the Houyhnhnms. It is uncertain exactly when Swift started writing Gulliver's Travels, but some sources suggest as early as 1713 when Swift, Gay, Pope, Arbuthnott and others formed the Scriblerus Club, with the aim of satirising then-popular literary genres. Swift, runs the theory, was charged with writing the memoirs of the club's imaginary author, Martinus Scriblerus. It is known from Swift's correspondence that the composition proper began in 1720 with the mirror-themed parts I and II written first, Part IV next in 1723 and Part III written in 1724, but amendments were made even while Swift was writing The Drapier's Letters.