The exact date that these two important texts of English literature were written is by no means certain and is even now subject to much scholarly debate. However, generally speaking, it is considered that Piers Plowman and the three fragments that have been collected in total were written in the late 14th century. Sir Gawain and the Green Knight is dated from the same period, with some critics claiming that is was written around 1375. However, the difference between these two poems is the way that it is recognised that Piers Plowman was actually written over several years, with the author spending about 20 years of his life devoted to this work. The first section, it is estimated, was written between 1367-70, so, ostensibly, if these dates are correct, Piers Plowman was written first chronologically, but took much longer to complete, whereas it is estimated Sir Gawain and the Green Knight was written in just one year before Langland completed his magnum opus.
Although both originate from the same time, they are both markedly different in subject and style, with Piers Plowman focusing on a Christian allegory and Sir Gawain and the Green Knight making extensive use of alliteration and magic from the time of King Arthur to give it its impact. Note the following example:
For these were proud princes, most prosperous of old,
Past all lovers lucky, that languished under heaven,
The extensive alliteration, as in the repetition of the "p" sounds and the "l" sounds, is a hallmark of this poem, whereas it is Christian symbolism and allegory that Piers Plowman is identified by.