Extremely little is known about the origins of Sir Gawain and the Green Knight. The poem survived the Middle Ages in a single manuscript that was preserved because it fell into the hands of a book collector, Sir Robert Cotton, whose collections were later donated to the British Museum. There, the poem was rediscovered by scholars during the early nineteenth century, and it has been recognized as a masterpiece of English literature ever since. The fact that the Sir Gawain and the Green Knight appears in only one manuscript should not be taken as evidence that it fell into immediate obscurity after it was written. In fact, many works of medieval literature have been lost to history or exist in only a handful of copies. Sir Gawain and the Green Knight was popular enough to have spawned a bad imitation, usually called The Greene Knight to distinguish it from the original.
The manuscript in which Sir Gawain and the Green Knight appears, known as Cotton Nero A.x., contains three other poems. On the basis of their similarities in style, language, and theme, all four are believed to be by the same poet. None of the poems has a title in the manuscript, but the three are usually called Pearl, Patience, and Cleanness (or Purity). Those three poems have more obviously religious themes than Sir Gawain and the Green Knight: Patience retells of the story of Jonah and the whale; Pearl offers a dream-vision of heaven; and Cleanness uses three episodes from the Bible (the Flood, Sodom and Gomorrah, and Balshazzar's Feast) to illustrate the ideal of purity. Some scholars believe that a fifth poem, Saint Erkenwald, found in a different manuscript, is also by the same poet. The Cotton Nero manuscript was most likely produced by a copyist, not the poet, and there is no way to determine how many copies away from the original it is. The manuscript itself dates around 1400, and scholars have dated the composition of the poems anywhere from about 1350 to 1400.
