The first edition of Pride and Prejudice was published in three volumes. Thomas Egerton issued Jane Austen’s novel in London on 28 January 1813 as a three-volume hardcover set, a common publishing format for novels in the Regency period.
This format is often called a “three-decker.” Libraries and circulating-library readers commonly encountered fiction in separate volumes, allowing a book to be borrowed and passed among subscribers more conveniently than a single large tome. The original edition was not presented with Austen’s name prominently on the title page; it was described as being by “the Author of Sense and Sensibility.”
The publication was commercially successful. Austen sold the copyright to Egerton for £110, receiving a fixed payment rather than sharing directly in the profits. The favourable reception helped the first edition sell out, and a second edition appeared later in 1813.
The number three refers to the physical volumes of the first edition, not to the novel’s chapters, parts, or later modern paperback divisions. Modern editions usually print the complete novel in one volume, which can make the original publication arrangement easy to overlook.