What is a sonnet cycle?

Answer 1

A Sonnet Cycle is a set of sonnets that usually tell a story (often a love story of some kind). In English the two first sonnet cycles were Philip Sidney's Astrophel to Stella - which tells the story of Astrophel's love for Stella - and Samuel Daniel's Delia, which is very similar.

Astrophel and Delia don't have much of a plotline (there is a faint one, if you read carefully), but W S Blunt's Esther has a clear story to tie the sonnets together (it is probably a heavily fictionalised account of his affair with Catherine Skittles Walters).

A group of sonnets which share a common theme, but don't tell a story, is often called a Crown of Sonnets. If the unifying factor is a story of some kind, Sonnet Cycle is the preferred term.

But many critics use Crown of Sonnets and Sonnet Cycle interchangeably (and few contemporary poets write either).