The Encyclopædia Britannica (Latin for ) is a general-knowledge English-language encyclopaedia. It has been published since 1768 and, after several ownership changes, is currently owned by Encyclopædia Britannica, Inc. The 15th edition, published in 2010, spans 32 volumes and 32,640 pages and was the last printed edition. Since 2016, it has been published online at Britannica.com.

Printed for 245 years, the Britannica was the longest-running in-print encyclopaedia in the English language. It was first published between 1768 and 1771 in Edinburgh, Scotland, in weekly instalments that came together to form three volumes. At first, the encyclopaedia grew quickly in size from edition to edition. The second edition expanded to 10 volumes, and by its fourth edition (1801–1810), it had expanded to 20 volumes. Since the beginning of the twentieth century, its size, measured as total word count, has remained roughly steady at about 40 million words.Jeff Loveland, "Why Encyclopedias Got Bigger ... and Smaller," Information and Culture 47 (2012): 244.

The Britannica has had many notable contributors. The 9th (1875–1889) and 11th editions (1911) are considered landmark encyclopaedias for scholarship and literary style. Following its acquisition in 1901 by an American firm and starting with the 11th edition, the encyclopaedia shortened and simplified articles to broaden its appeal to the North American market. Though published in the United States since 1901, the Britannica has mostly maintained British English spellings.

In 1932, the Britannica adopted a policy of "continuous revision," in which the encyclopaedia is continually revised and reprinted, with every article updated on a schedule.Paul Kruse, "The Story of the Encyclopaedia Britannica, 1768-1943," PhD dissertation (University of Chicago, 1958), 389. The publishers of Compton's Pictured Encyclopedia had already pioneered such a policy.M. A. Khan, The Principles and Practice of Library Science (New Delhi: Sarup and Sons, 1996), 281.

The 15th edition (1974–2010) has a three-part structure: a 12-volume of short articles (generally fewer than 750 words), a 17-volume of long articles (two to 310 pages), and a single volume to give a hierarchical outline of knowledge. The was meant for quick fact-checking and as a guide to the ; readers are advised to study the outline to understand a subject's context and to find more detailed articles.

In the 21st century, Britannica faced competition: initially from the digital and multimedia encyclopaedia Microsoft Encarta, Note that in 1985 Microsoft approached Encyclopaedia Britannica to collaborate on digitizing and releasing Britannica's material on CD-ROM; this collaboration did not eventuate, and Microsoft then pursued deals with other encyclopaedia companies (including Funk and Wagnalls) instead. and later from the online mass-collaboration encyclopaedia Wikipedia. While it continued to score well in assessments of overall quality, compared to its competitors, it could not (as an expert-authored compilation of a limited number of articles on important subjects only) match their breadth of coverage and continuous updating.

In March 2012, it announced it would no longer publish printed editions and would focus instead on the online version.

History

Past owners have included, in chronological order, the Scottish printers Colin Macfarquhar and Andrew Bell, the Scottish bookseller Archibald Constable, the Scottish publisher A. & C. Black, Horace Everett Hooper, Sears Roebuck, William Benton, and Jacqui Safra, a Swiss billionaire residing in New York.

Recent advances in information technology and the rise of electronic encyclopaedias such as Encyclopædia Britannica Ultimate Reference Suite, Encarta and Wikipedia have reduced the demand for print encyclopaedias. To remain competitive, Encyclopædia Britannica, Inc. has stressed the reputation of the Britannica, reduced its price and production costs, and developed electronic versions on CD-ROM, DVD, and the World Wide Web. Since the early 1930s, the company has also promoted spin-off reference works. Aside from providing a summary of the Britannica history and early spin-off products, this article also describes the life-cycle of a typical Britannica edition. A new edition typically begins with strong sales that decay as the encyclopaedia becomes outdated. When work on a new edition is begun, sales of the old edition stop, just when fiscal needs are greatest: a new editorial staff must be assembled, articles commissioned. Elkan Harrison Powell identified this fluctuation of income as a danger to any encyclopaedia, one he hoped to overcome with continuous revision.

Editions The Encyclopaedia Britannica has been issued in 15 editions, with multi-volume supplements to the 3rd edition and to the 4th, 5th, and 6th editions as a group (see the Table below). The 5th and 6th editions were reprints of the 4th, and the 10th edition was only a supplement to the 9th, just as the 12th and 13th editions were supplements to the 11th. For the 15th edition (1974), the Britannica underwent a massive reorganization and became the New Encyclopaedia Britannica. The 14th and 15th editions were edited every year throughout their runs, so that later printings of each were quite different from early ones.

Throughout its history, the Britannica has had two aims: to be an excellent reference book, and to provide educational material. In 1974, the 15th edition adopted a third goal: to systematize all human knowledge.

The history of the Britannica can be divided into five eras, punctuated by changes in management or reorganization of the encyclopaedia.

1768–1824

In the first era (1st–6th editions, 1768–1824), the Britannica was managed and published by its founders, Colin Macfarquhar and Andrew Bell, and by Archibald Constable.

The Britannica was first published in serial instalments between December 1768 and about August 1771 in Edinburgh as the Encyclopædia Britannica, or, A Dictionary of Arts and Sciences, compiled upon a New Plan.Richard Yeo, Encyclopaedic Visions: Scientific Dictionaries and Enlightenment Culture (Cambridge: Cambridge University Press, 2001), 176. The new plan in question was an organizational one, namely to include two kinds of typographically distinct entries (articles and longer "treatises") in a single alphabetical sequence. In principle, "treatises" were to cover the arts and sciences, leaving articles to deal with their subordinate objects. The idea may have been inspired by Dennis de Coetlogon's Universal History of Arts and Sciences, an alphabetical encyclopaedia that contained only treatises.Kafker and Loveland, "William Smellie's Edition," 23-24. Regardless, the Britannica continued to intermix formally distinguished articles and treatises through the 10th edition.Jeff Loveland, “Unifying Knowledge and Dividing Disciplines: The Development of Treatises in the Encyclopaedia Britannica,” Book History 9 (2006): 73-74.

According to Arthur Herman's book How the Scots Invented the Modern World, the Encyclopaedia Britannica is one of the most enduring legacies of the Scottish Enlightenment. It is important to be more specific, however, about how the early Britannica was and was not Scottish and a monument to the Scottish Enlightenment. The two publishers and William Smellie, whom they engaged to compile the work, were all Scots. Much of the first edition was compiled by Smellie from Scottish sources.Richard B. Sher, The Enlightenment & the Book: Scottish Authors & their Publishers in Eighteenth-Century Britain, Ireland & America (Chicago: University of Chicago Press, 2006), 135-36. At the same time, despite working in Edinburgh, the centre of the Scottish Enlightenment, neither Smellie nor James Tytler, the editor of the second edition, arranged for contributions from any local luminaries. Nor does the work seem to have been much noticed by participants in the Scottish Enlightenment before its third edition.Yeo, Encyclopaedic Visions, 172-73. Likewise, it is significant that the title chosen was the Encyclopaedia Britannica (and not the Encyclopaedia Scotorum, or 'Scottish Encyclopaedia'). Indeed, by the time of the third edition, the Britannica was starting to evolve into a symbol of Britishness.Kathleen Hardesty Doig et al., “Colin Macfarquhar, George Gleig, and Possibly James Tytler's Edition (1788-97): The Attainment of Recognition and Eminence,” in Early Britannica, 249.

In this era, the Britannica grew significantly in size, sales, and reputation. Just as important were changes to the way it was compiled and edited. On his tombstone, Smellie was characterized as the editor of the first edition of the Britannica, but he was not an editor in anything like the sense in which Macvey Napier, who edited the Supplement to the Fourth, Fifth, and Sixth Editions, was. Smellie compiled nearly all the articles in the first edition himself, although we know he had minor help from at least one contributor, James Anderson, who wrote the articles "Dictionary," "Pneumatics," and "Smoke."Kafker and Loveland, "William Smellie's Edition," 19-20. For the third edition and its Supplement, editors still compiled the bulk of the articles, but they were assisted by dozens of collaborators. We know of thirty-five who wrote for the third edition, for example, some of them named in the preface, including the chemist Joseph Black and the natural philosopher John Robison.Doig et al., "Colin Macfarquhar, George Gleig, and possibly James Tytler's Edition," 169-71. Then, by the time of the Supplement, Napier had become mostly a managing editor. He still wrote some articles, but his main job was recruiting collaborators, for the prospectus stipulated that "the various articles, in the Supplement, shall be written by the most Eminent Men, in the different departments of Science."Yeo, Encyclopaedic Visions, 251, 257.

Several other encyclopaedias competed with the Britannica throughout this period, among them editions of Ephraim Chambers' and Abraham Rees's Cyclopædia, Coleridge's Encyclopædia Metropolitana, and David Brewster's Edinburgh Encyclopædia.

1827–1901 During the second era (7th–9th editions, 1827–1901), the Britannica was managed by the Edinburgh publishing firm A & C Black. Although some contributors were again recruited through friendships of the chief editors, notably Macvey Napier, others were attracted by the Britannica reputation. The contributors often came from other countries and included the world's most respected authorities in their fields. A general index of all articles was included for the first time in the 7th edition, a practice maintained until 1974.

Production of the 9th edition was overseen by Thomas Spencer Baynes, the first English-born editor-in-chief. Dubbed the "Scholar's Edition", the 9th edition is the most scholarly of all Britannicas. After 1880, Baynes was assisted by William Robertson Smith. No biographies of living persons were included. James Clerk Maxwell and Thomas Huxley were special advisors on science. However, by the close of the 19th century, the 9th edition was outdated, and the Britannica faced financial difficulties.

1901–1973

In the third era (10th–14th editions, 1901–1973), the Britannica was managed by American businessmen who introduced direct marketing and door-to-door sales. The American owners gradually simplified articles, making them less scholarly for a mass market. The 10th edition was an eleven-volume supplement (including one each of maps and an index) to the 9th, numbered as volumes 25–35, but the 11th edition was a completely new work; its owner, Horace Hooper, lavished enormous effort on the project.