This technical term provides a good example of the mis-named, the loosely-defined, the nameless and the only-belatedly-named in Middle English poetics.  It’s a word sometimes flung about by my students when close-reading: any syntactical break (i.e. anywhere a line of poetry has a division between grammatical phrases or clauses, and especially if it’s near the middle of the line) gets called a caesura without too much thought.  It’s one of those technical terms that gives you faux expertise: you can spot something easy (i.e. a syntactic break) and label it with a word which makes it seem as if you are analysing the metre.  Joseph A Dane is usefully strict about how relevant the word is for Chaucer’s metre in this article (the answer is not very!).

The word itself (deriving from the verb ‘to cut’) comes from Latin metrical theory.  Here it describes the situation which occurs when the gap between words does not align with the break between metrical feet (i.e. where the end of a word occurs in the middle of the foot rather than at the end).  Some types of metre require or encourage a word-break which is not aligned with a foot-break (that is, a caesura, as opposed to diaeresis, where the word-break and the break between feet coincide) at a certain point in the line.

As often in poetics, theorisers borrow a word from another language’s technical terms and use it with a related but different meaning (just as we’ve done with Greek terms like iamb and dactyl).  Caesura is used somewhat loosely by scholars of Middle English verse to refer to pauses in a line of verse, whether metrical, syntactical or rhetorical (i.e. a pause added for emphasis or dramatic effect).  It might not matter much, in the grand scheme of things, but calling a syntactical or rhetorical pause a caesura muddies the waters as to what is a metrical feature (i.e. what plays a part in the vast majority of lines) and what is a feature of the rhythm of an individual line.

Several different types of Middle English verse regularly divide their lines up into two half-lines (also sometimes called hemistichs), sometimes of equal length and with the same metrical structure, sometimes of different lengths and sometimes with different metrical structures.  When the caesura is a structural feature of the vast majority of lines, this creates certain expectations for the reader and constraints for the writer.  The line’s syntax has to be constructed by the poet to have a break at a certain point.  A word won’t be split across the gap.  Yet norms are not unbreakable rules: the patterns of sense and syntax work with and against the pattern of the caesura.  Macklin Smith has a great essay showing how Langland varies the impact of the caesura in the line and at times uses syntax to resist the underlying pattern of the mid-line break.

According to Nicholas Myklebust’s wonderfully detailed PhD study, Chaucer’s decasyllabic line does have syntactic and rhetorical pauses, but doesn’t have regular metrical caesurae (so I hereby ban St Edmund Hall students from talking about caesurae in their Troilus commentaries).  Chaucer’s lines may have syntactical and/or rhetorical pauses, but this is not a feature of every line.  Myklebust’s PhD also shows that whereas Chaucer and Hoccleve did not have a regular metrical caesura, Lydgate divides each of his lines into two half-lines.  Lydgate draws on French practice in vers de dix which (in some varieties at least) had a caesura at a fixed point after the fourth syllable in the line.

As Myklebust explains very brilliantly, the word before the mid-line break is rather like a line ending (i.e. a place where self-imposed constraints and self-allowed licences might apply).  We’re used to licences and constraints at the line end: most obviously rhyme, but also in ‘classical’ alliterative poetry, where lines must end with an unstressed final syllable, whilst Chaucerian decasyllabics allow an unstressed syllable after the final beat.  Similar things go on at the ending of the first half-line.  The word before might have to rhyme with the word at the end of the line (creating what is often called medial rhyme).  The poet might impose the constraint that the syllable before the caesura should be a monosyllable or a strongly stressed syllable.  Poets might also allow themselves licences to do things at the caesura which they might not do elsewhere in the line.  Lydgate, as Myklebust explains, uses the licence of the caesura to add or delete a syllable.  He was not a poor metrist who couldn’t count to ten, but rather a poet who divided his decasyllable line into two parts and allowed himself metrical licences at the caesura.

Despite its presence in several different types of Middle English verse, I can’t find any naming or discussion of regular pauses built into the structure of the line much before the middle of the sixteenth century.  It is understood as one element of the self-imposed constraints of poetic form, but it is neither named nor theorised in relation to medieval English verse (at least as far as I can see in my research to date).  The earliest usage of the word itself seems to be by Archbishop Matthew Parker, when giving advice to the lay reader on the reading through of English psalms in preparation for singing (1567).  In giving this advice, Parker is still thinking of psalmody rather than prosody, how to read these English translations in imitation of Latin psalm-singing.  He writes: ‘Observe the trayne: the ceasure marke, / To rest with note in close: / Rythme-dogrell playne: as dogs do barke, / ye make it els to lose.’ [Pay attention to the rhythm, mark the caesura, so as to end with the rhythm in a proper cadence: otherwise you will make it too loose, like the doggerel rhyme which currish poets bark].

Even if it wasn’t theorised or articulated, perhaps an understanding of the caesura in Middle English decasyllabic poetry survived through the fifteenth century and into the sixteenth?  Arts of poetry for English and Scottish versifying written in the second half of the sixteenth century were the first to discuss the caesura.  George Gascoigne writes about the caesura in his Certayne Notes of Instruction concerning the making of verse or ryme in English (1575).  In lines of ten syllables, Gascoigne says the caesura should come after the fourth syllable (which would usually be a stressed syllable in a line alternating between weak and strong stresses), but he says that in rhyme royal it is up to the writer as to where any pause falls.  Though Lydgate did of course write rhyme royal stanzas and Chaucer wrote in couplets, I wonder if Gascoigne here is trying to articulate the difference between Lydgate’s metre and what he found in Chaucer’s Troilus, for example.

Puttenham (Arte of English Poesie, 1589) likewise describes something which might be gesturing at Lydgate’s line: ‘the meter of ten syllables is very stately and heroical and must have his caesura fall upon the fourth syllable’.  Puttenham also notes that Chaucer and Lydgate in their couplet verse don’t use the caesura or use it very unpredictably.  This is not really accurate (as both poets wrote in both forms but with different metres, one with a caesura and one without), but it works as a rough way of contrasting Lydgate’s rhyme royal in the Fall of Princes (stately, heroical) and Chaucer’s decasyllabic couplets in the Canterbury Tales.