The fifteenth-century Middle English romance Sir Gowther is known to exist in only two manuscripts, Edinburgh Advocates MS. 19.3.1 and British Library Royal MS. 17.B.XLIII. The texts of the two manuscripts, however, differ from each other in substantive readings in more than 50 percent of the lines. In her analysis of the Advocates manuscript, Phillipa Hardman found that each of the three romances in that manuscript, Sir Gowther, Sir Isumbras, and Sir Amadace, has a text significantly different from the other known manuscripts of each poem. She concluded that these texts had been edited, probably by the scribe of most of the Advocates manuscript, Heege.