The paper discusses the authorship of the Cornish language mystery play Gwreans an bys, or, The Creacion of the World with Noye's Fludde. Scholars are uncertain whether William Jordan, the scribe, was the author or just the transcriber of the play. The earliest manuscript of the play states that it was written by William Jordan on August 12, 1611. Neuss suggests that the play was written later than 1500 based on language and a possible link to the re-establishment of Catholicism under Mary after 1553. Some suggest a pre-Reformation date of about 1530 due to the presence of Roman Catholic doctrinal elements. The 1611 version is seen as a third-generation copy, possibly the start of a commonplace book to preserve the declining Cornish language.