Alexandrine is a name used for several distinct types of verse line with related metrical structures, most of which are ultimately derived from the classical French alexandrine. The line's name derives from its use in the Medieval French Roman d'Alexandre of 1170, although it had already been used several decades earlier in Le Pèlerinage de Charlemagne. The foundation of most alexandrines consists of two hemistichs (half-lines) of six syllables each, separated by a caesura :o o o o o o | o o o o o o o=any syllable; |=caesura

The French alexandrine is a syllabic poetic metre of 12 syllables with a medial caesura dividing the line into two hemistichs (half-lines) of six syllables each. It was the dominant long line of French poetry from the 17th through the 19th century, and influenced many other European literatures which developed alexandrines of their own.