The recent reintroduction of the notion of cycle into critical discussion of medieval romance has not enjoyed the unanimity of definitions that characterize the use of the term interlace since Ferdinand Lot. Let us turn therefore to the ancient and medieval past when cyclicity had a more precise meaning which we can use to approach the Lancelot-Grail as a cycle of interlacing narratives. David Staines has noted Horace's reference to cyclic poets in the Art of Poetry lines 131–9 and their ‘tendency to diffuseness.’ Although there is a ‘gathering of literary creations that have the same general subject-matter, or … a major episode or time around which they are loosely ordered,’ the ‘cyclic writer has no sense of structure or proportion, and his creation is formless and disunified, finding its development only in the natural chronology of the related events.’ Is the Prose Lancelot ‘tediously and monotonously complete’ because its author or authors followed ‘a strict chronology and exercised no selectivity in the employment of materials’?

Scholars have noted the prose romance's careful chronology. Moreover, although nineteenth-century scholars identified it as a cycle because Arthur was a central figure, they also decried its seemingly monotonous, formless, and disunified combination of disparate adventures. But after Lot, this criticism declined in favor of greater appreciation of the work's careful interlace. Does interlace bring together in a coherent way the fabric of the prose romance? And if so, is it still a cycle?

Before attempting to answer these questions, let us look again briefly at Horace's references to the scriptor cyclicus. According to Horace, the cyclic writer's principal fault is violation of the operis lex, or the coherent union of parts in a beginning, middle, and end. This occurs when the work begins in a past so distant that its author is unable to get to its real subject-matter and thence to a conclusion. It also occurs when digressions become so numerous and extensive as to be useless; the plot goes off track, finally producing a sense of endless, monotonous byways that end in arid wastes. Although such a cycle may have a bold, striking beginning, it quickly turns turgid or obscure. Ideally, narrative should be coherent; in such cases, even if the beginning is obscure, the obscurity will gradually clear up, revealing a coherent plot.