Dodecasyllable
Dodecasyllable verse is a line of verse with twelve syllables. 12 syllable lines are used in a variety of poetic traditions.
Dodecasyllabic meter was invented by Jacob of Serugh, a Miaphysite bishop.
With the so-called "political verse" it is the main metre of Byzantine poetry. It is also used in Italian and French poetry, and in poetry of the Croats. In an Anglo-Saxon and French context, the dodecasyllable is generally called the "alexandrine", after the French equivalent.