This massive work has been reprinted many times over the years in various editions.
THE ORIGINAL was published between 1776 and 1789 in six volumes by the firm of Strahan & Cadell, in the Strand, London.Data assembled from David Womersley, ed., Edward Gibbon - The History of the Decline and Fall of the Roman Empire, vol. 1 (London: Allen Lane, 1994), pp. cvii, 1084, 1106; and Norton, Biblio, 36-63. Norton reported that reliable figures on printed copies of all editions and volumes "cannot, unfortunately, be stated." p. 52. Precise days of publication from Norton, Biblio, except where otherwise noted.
Volume I has a complex history of its own. It was published in six editions between 1776 and 1789. Three of the six contain authorial revisions, marked AR:
First editions, 1776 Feb 17 (a and b-AR), 1000 copies;
Second edition, 1776 June 3; 1500 copies;
Third edition, 1777 May (AR); 1000 copies;
Fourth edition, 1781 Apr 4 (AR);
Fifth editions, 1782 Apr 11 (a and b);
Sixth edition, 1789 Dec 1.
Volumes II, III were published together in three editions between 1781 and 1789:
First editions, 1781 Mar 1 (a and b; b sometimes called the second edition);