1817, from Edmund Spenser (c. 1552-1599), Elizabethan poet (for the origin of the surname, see Spencer). Spenserian stanza, which he employed in the "Faerie Queen," consists of eight decasyllabic lines and a final Alexandrine, with rhyme scheme ab ab bc bcc.
"The measure soon ceases to be Spenser's except in its mere anatomy of rhyme-arrangement" [Elton, "Survey of English Literature 1770-1880," 1920]; it is the meter in Butler's "Hudibras," Scott's "Lady of the Lake," and notably the "Childe Harold" of Byron, who found (quoting Beattie) that it allowed him to be "either droll or pathetic, descriptive or sentimental, tender or satirical, as the humour strikes me; for, if I mistake not, the measure which I have adopted admits equally of all these kinds of composition."