Dactylic hexameter
Dactylic hexameter (also known as "heroic hexameter" and "the meter of epic") is a form of meter or rhythmic scheme in poetry. It is traditionally associated with the quantitative meter of classical epic poetry in both Greek and Latin and was consequently considered to be the Grand Style of classical poetry. The premier examples of its use are Homer's Iliad and Odyssey, Virgil's Aeneid, and Ovid's Metamorphoses.
Structure
The meter consists of lines made from six (in Greek ἕξ, hex) feet, hence "hexameter". In strict dactylic hexameter, each of these feet would be a dactyl (a long and two short syllables), but classical meter allows for the substitution of a spondee (two long syllables) in place of a dactyl in most positions. Specifically, the first four feet can either be dactyls or spondees more or less freely. The fifth foot is frequently a dactyl (around 95% of the time in Homer).
Because of the anceps (a short or long syllable), the sixth foot can be filled by either a trochee (a long then short syllable) or a spondee. However, because of the strong pause at the end of the line (which prevents elision and correption between lines in the dactylic hexameter), it is traditionally regarded as a spondee. Thus the dactylic line most normally looks as follows: