With Chaucer we have the first deliberate use of the five-stress couplet, in continuous verse, known to English poetry. His earliest use of the pentameter line was in the _Compleynt to Pitee_ (perhaps written about 1371), in the "rime royal" stanza; his earliest use of the pentameter couplet was in the _Legend of Good Women_, usually dated 1385. From that time the measure became almost his only instrument, and we find altogether in his poetry some 16,000 lines in the couplet, besides some 14,000 more in rime royal. Too much praise cannot be given Chaucer's use of the couplet. Although it was an experiment in English verse, it has perhaps hardly been used since his time with greater skill. He used a variety of cesuras (see ten Brink's monograph for the enumeration of them), a very large number of feminine endings (such as the still pronounced final-_e_ and similar syllables easily provided), free inversions in the first foot and elsewhere, and many run-on lines (in a typical 100 lines some 16 run-on lines and 7 run-on couplets appearing). The total effect is one of combined freedom and mastery, of fluent conversational style yet within the limits of guarded artistic form. "Much more regularly than the French and Provençals, and yet without pedantic stiffness, he made his verse advance with a sort of iambic gait, and he was therefore able to give up and exchange for a freer arrangement the immovable cesura, which these poets had always made to coincide with a foot-ending." (Ten Brink, in _English Literature_, Kennedy trans., vol. ii. p. 48.) On Chaucer's verse, see, besides the monograph of ten Brink already cited, Lounsbury's _Studies in Chaucer_, vol. iii. pp. 297 ff., and Schipper, vol. i. pp. 442 ff.