sonnet, poem of 14 lines, usually in iambic pentameter, restricted to a definite rhyme scheme. There are two prominent types: the Italian, or Petrarchan, sonnet, composed of an octave and a sestet (rhyming abbaabba cdecde), and the Elizabethan, or Shakespearean, sonnet, consisting of three quatrains and a couplet (rhyming abab cdcd efef gg). Variations of these schemes occur, notably the Spenserian sonnet, after Edmund Spenser (rhyming abab bcbc cdcd ee). The sonnet is generally believed to have developed from medieval songs. In Italy, where it was cultivated during the Renaissance, it achieved great expression in the work of Petrarch, Dante, Tasso, and Michelangelo. The form was introduced into Spain by Almogáver, into Portugal by Camões, into France by Saint-Gelays and Marot, and into England by Wyatt and Surrey. The sonnet came into prominence in Germany during the romantic period in the work of Goethe, Schlegel, Heyse, and others. Innumerable sonnets and sonnet sequences appeared in Elizabethan England, notably by Sidney, Spenser, and Shakespeare. Around the time of Milton's great sonnets, the use of the form began to decrease, but with the advent of romanticism in the early 19th cent. the sonnet again achieved popularity in the poetry of Wordsworth and Keats. Poets such as Elizabeth Barrett Browning, the Rossettis, and George Meredith in the 19th cent. and Dylan Thomas and W. H. Auden in the 20th cent. also wrote sonnets. American poets noted for their sonnets include Longfellow, E. A. Robinson, Elinor Wylie, and Edna St. Vincent Millay.
See S. Burt and D. Mikics, The Art of the Sonnet (2010).