The library of Jonathan Swift was sold by auction after his death in 1745. Fortunately, there is the auction catalogue, printed in 1746, so we know most of the books Swift owned at the time of his death. The catalogue lists a total of 657 lots. Earlier in his life, Swift had formed a habit of drawing up lists of the books he had read or owned. The first extant, of his reading, dates from 1697/1698, when he was employed by his mentor Sir William Temple. Another inventory of books he owned, Swift compiled in 1715. Although the sale catalogue was published in facsimile by Harold Williams as Dean Swift's Library (Cambridge, 1932), and the 1715 inventory twice (by T.P. LeFanu in 1927 and by William LeFanu in 1988), a thorough and minute description of the volumes in Swift's library has not been undertaken so far. The first part of this handbook, in four volumes, concentrates on the library proper. All individual books are described with a full collational formula, the complete contents, and remarks on the history and transmission of the text, on the life of the author, and on the significance of his writings for a late seventeenth- or early eighteenth-century reader. In order to provide a contemporary assessment of an author's status in Swift's day, the reader always finds a transcription of the relevant entry from the English translation (in two bulky volumes) of Moréri's The Great Historical, Geographical and Poetical Dictionary (1694), a work also on Swift's shelves. Swift's own copies have been consulted whenever their exact locations are known in European and North American libraries. Moreover, most marginalia and inscriptions have been scrupulously consulted and checked against existing printed versions. They are also fully transcribed. Where Swift is known to have quoted from, referred to or alluded to an author, all identified passages in Swift's writings are presented and discussed. Swift may have consulted many works in the libraries of his friend Thomas Sheridan or of Sir William Temple. Therefore, volume IV contains a transcript of the sale catalogue of Sheridan's library (1739) and a tentative list of Temple's library, reconstructed from references in Temple's works and secondary sources. In volume IV, the reader will find an index of references to Swift's works that enables him to consult this handbook when using the current standard editions of the Dean's poems, prose and correspondence, as well as further indexes of subjects, printers and authors.