Iteration refers to the repetition or renewal of something. In poetry, it involves repeating a word or phrase at the same point within each stanza, making it part of the verse form rather than incidental repetition. This repetition creates a point of linkage within the stanza. Sometimes the link is not exact but instead involves a repetition of the same root word in a different tense or form, or a punning link where the same word appears in two different senses.
Structurally, iteration appears in Middle English poetry only at the point where a stanza might be split into two parts. For example, in a twelve-line stanza with the rhyme scheme ababababcdcd, iteration occurs to link lines 8 and 9, joining the last b-rhyme line to the first c-rhyme line. Stanzas where rhymes cross over, such as the octave ababbcbc pattern, do not feature iteration.
Not all stanzas that could be split without crossing rhyme include iteration. Many poets were indifferent to this feature. However, iteration often co-occurs with other forms of formal complexity, such as stanza-linking or alliteration, and is employed by poets conscious of their craft. It appears in various stanza types and genres, including alliterative-stanzaic poetry, political songs, love lyrics, moral lyrics, and short narratives.
One type of iteration links a sequence of monorhymed lines to a final couplet, while another connects longer lines to a shorter section called a 'wheel.' This feature indicates that Middle English stanzas could have subdivisions, similar to the octave and sestet of a sonnet. Modern critics use terms like frons ('forehead' or 'front'), cauda ('tail'), and sirma ('train') for these subdivisions, drawing from Dante's discussion in De Vulgari Eloquentia. Between these sections lies the diesis, where the melody changes, akin to the volta of a sonnet. However, unlike in sonnets, some Middle English poets prioritized linking stanzas over splitting them.
Another way to link longer lines with a shorter wheel was the 'bob,' a single short line rhyming with one of the wheel's lines. In Sir Gawain and the Green Knight, the bob effectively replaces iteration, serving as a free-floating linking phrase. Similarly, the stanza form used by the Awntyrs of Arthur poet innovated beyond iteration. The stanza rhymes ababababcdddc, with iteration at lines 8 and 9. The ninth line matches the metre of the first eight, linking by both metre and iteration. Later poets imitating this stanza, such as in Gologras and Gawain, opted to link by metre and not iteration, leading to its decline in popularity.
Despite its diminished use, iteration remained a possibility in certain genres, such as hymns praising saints and psalm paraphrases, as demonstrated by scholars like Ruth Kennedy and Susanna Fein.