According to the Translators' Note, this edition is based on the completely revised version of the original edition (1928-29) which was published in 1954. Never before translated into English, it ""is distinguished not only by the addition of a considerable body of new biographical material. . . but also by a new point of view,"" focusing less on Ibsen's contribution to history and more on his psychological insight and craftsmanship. Prodigious and, from all indications, authoritative.