The sonnet is a fourteen-line lyric poem in predominantly iambic pentameter, with a formal rhyme scheme. Although there can be considerable variation in rhyme scheme, most English sonnets are written in either the Italian (Petrarchan) style or the English (Shakespearean) style. A third sonnet form, the Spenserian sonnet, is also well-known, but far less commonly used than either the Petrarchan or the Shakespearean sonnet.
THE PETRARCHAN SONNET
The Italian sonnet form is commony called the Petrarchan sonnet, because Petrarch's "Canzonieri," a sequence of poems including 317 sonnets, established the sonnet as a major form in European poetry. The Petrarchan sonnet consists of an octave (an eight-line stanza), rhyming abbaabba, and a sestet (a six-line stanza), rhyming cdcdcd, or cdecde--or using some other variation of the cd or cde patterns, but without a final rhymed couplet.
The octave usually presents an idea, raises an argument, makes a proposition, or poses a problem. A turning point ("volta") occurs between the octave and the sestet, and the sestet develops out of the octave by illustrating the idea in the octave, varying it, responding to it, or solving the problem it poses.
THE SHAKESPEAREAN SONNET
Shakespeare did not invent the English sonnet form, but he is recognized as its greatest practitioner; therefore, the English sonnet is commonly called the Shakespearean sonnet.
The Shakespearean sonnet consists of three quatrains (four-line stanzas), rhyming abab cdcd efef, and a couplet (a two-line stanza), rhyming gg. Because each new stanza introduces a new set of rhyming sounds, the Shakespearean sonnet is well-suited to English, which is less richly endowed than Italian with rhyming words.
As with the structure of the Petrarchan sonnet, that of the Shakespearean sonnet influences the kinds of ideas that will be developed in it. For example, the three quatrains may be used to present three parallel images, with the couplet used to tie them together or to interpret their significance. Or the quatrains can offer three points in an argument, with the couplet serving to drive home the conclusion.
THE SPENSERIAN SONNET
In his "Amoretti" Edmund Spenser used the sonnet form named after him. The Spenserian sonnet has three quatrains, rhyming abab bcbc cdcd, followed by a couplet, rhyming ee. The linked rhymes of his quatrains suggest the linked rhymes of such Italian forms as terza rima.
The sonnet probably originated among the Sicilian court poets of the thirteenth century, who were influenced by the love peotry of the Provencal troubadours. It then spread to Tuscany, where it reached its highest expression in Petrarch's "Canzonieri," a sequence of love poems addressed to "Laura," his idealized beloved.
THE SONNET IN ENGLISH POETRY
The sonnet, along with other Italian forms, was introduced to England in the sixteenth century by Sir Thomas Wyatt and his younger contemporary Henry Howard, Earl of Surrey. Both poets translated several of Petrarch's sonnets--often the same ones--as well as composing their own.
The new poetic form seems to have inspired the flowering of English lyric poetry in subsequent decades, reaching its peak during the reign of Elizabeth I. During the Elizabethan period the sonnet often appeared as part of a sequence of love poems, in the manner of Petrarch's "Canzonieri." The Elizabethans were particularly attractee to the complexity of a sequence in which each sonnet was both an independent poem and part of an ongoing narrative development. Many poets employed conventional images and patterns of thought in their sonnets, but the most skilled mangaed to create tension and complexity by playing against the conventions even as they made use of them.
Among notable Elizabethan sonnet sequences (Sir Philip Sidney's "Astrophel and Stella"; Samuel Daniel's "Delia"; Edmund Spenser's Amoretti") Shakespeare's sequence of one hundred twenty sonnets addressed to a "dark lady" and a "fair young man" is considered to be the greatest.
In the seventeenth century John Donne's "Holy Sonnets" used the sonnet sequence as a vehicle for religious themes. John Milton wrote sonnets on religious and political themes, as well as on such personal subjects as his own blindness.
In the nineteenth century the love sonnet sequence was revived in Elizabeth Barrett Browning's "Sonnets from the Portuguese" (1850) and in Dante Gabriel Rosetti's "The House of Life" (1876).
Even after five centuries the sonnet still attracts the attention of serious poets, partly because of the challenge provided by the rigorous constraints of its fixed form, and partly because of its long tradition of use by most of the important poets in the English language.