How did French literary influence change English poetic rhythms during the Middle English period?

During the Middle English period, French literary influence significantly altered English poetic rhythms by encouraging the transition from traditional alliterative verse to rhymed forms.12

While Old English poetry relied on a four-stress line governed by alliteration, the post-conquest period saw rhyme begin to supplant this structure. By the late 12th century, French models had become so pervasive that many English poets began experimenting with rhymed couplets and varied meters, often mixing them with native alliterative techniques in works like the Brut and The Proverbs of Alfred.12

This shift toward French-influenced prosody introduced greater metrical regularity. For instance, The Owl and the Nightingale (written after 1189) demonstrates an early, assured use of octosyllabic couplets, a form characteristic of French verse. Unlike the purely syllabic meters dominant in French poetry—where the count of syllables is fixed but stress is variable—English poets gradually adapted these influences into their own syllable-stress traditions. This evolution reflected broader changes in literary taste as English poets moved away from the rigid, set types of classical Old English verse toward more flexible, rhymed structures.231