The tale of Sir Gawain
Sir Gawain and the Green Knight is a unique poem which not only tells the tale of a knight (or "knyyt" as it is written in the Middle-English manuscript) who goes on a quest, but also provides a subtle criticism of Arthurian legend by way of telling us how Sir Gawain is a "pearl amid white peas" when he is evaluated by the Green Knight late in the tale (line 2065).
Why is Sir Gawain and the Green Knight important?
This poem consists of 2530 lines that are arranged into 101 stanzas. It is commonly considered to be a part of the 14th century "Alliterative Revival" and is written in a language dialect that is from the English northwest Midlands estimated to be in the vicinity of Lancashire, Cheshire and Derbyshire. As such, the "Pearl Poet" (most common designation for Sir Gawain and the Green Knight's unknown author, though he is also referred to by some as "the Gawain Poet") is classified as a "northern poet" in contrast to, for example, a "southern poet" like Geoffrey Chaucer.
The "Alliterative Revival" was a form of poetry that hearkened backward to pre-Norman conquest Anglo-Saxon poetry that emphasized accented meter instead of syllabic rhyming (such as Chaucer).
Sir Gawain and the Green Knight is usually described as a fusion between two main poetic subject traditions: French romance and Celtic literature.
HONI SOYT QUI MAL PENCE*
* The book (from the Cotton Nero A.x. manuscript) ends with "HONI SOYT QUI MAL PENCE" - This is a Anglo-Saxon motto derived from Old French meaning roughly "shame to he who thinks evil of it" though it is more often streamlined to be "shame to him who finds evil here"