Sonnet

The sonnet is a rhymed verse form of 14 lines.

History
The form originated in Sicily, and became used throughout Italy during the late 13th and early 14th centuries. From there it spread to other countries of western Europe, acquiring slightly different characteristics in each.

The sonnet was introduced into England, in its Petrarchan form, by Thomas Wyatt, and was taken up by other poets, notably William Shakespeare. It has continued in use, despite criticisms of its inadequacy.

Form
As standardised by Petrarch, the sonnet had 14 lines, of 11 syllables each. The first eight lines rhyme abbaabba. The remaining six may use two or three rhymes combined in a variety of ways. There is a change of direction in thought after the first eight.

The French sonnet normally has 12 syllables.

In England, Wyatt and Howard established the iambic pentameter as normal, but the Elizabethans adopted a new rhyme scheme, ababcdcdefefgg, though Spenser had a rhyme scheme of his own. Later writers have introduced other variations. The break in the thought has frequently been omitted.

A defence of the sonnet
Scorn not the Sonnet; Critic, you have frowned,
 * Mindless of its just honours; with this key
 * Shakespeare unlocked his heart; the melody
 * Of this small lute gave ease to Petrarch's wound;
 * A thousand times this pipe did Tasso sound;
 * With it Camöens soothed an exile's grief;
 * The Sonnet glittered a gay myrtle leaf
 * Amid the cypress with which Dante crowned
 * His visionary brow; a glow-worm lamp,
 * It cheered mild Spenser, called from Faery-land
 * To struggle through dark ways; and when a damp
 * Fell round the path of Milton, in his hand
 * The Thing became a trumpet, whence he blew
 * Soul-animating strains — alas, too few!

William Wordsworth