This is a freely available online bilingual (Welsh and English) standard critical edition of the poetry of Guto’r Glyn (c.1435-c.1490). Guto’r Glyn is regarded as one of the most accomplished poets of late medieval Wales. As well as providing the user with translations of the poetry and paraphrases into modern Welsh, there are copious notes on the poems, the patrons, their homes, on the historical background and any notable linguistic features. Each poem is also accompanied by images from the most important manuscript witnesses (provided by the National Library of Wales), as well as transcriptions.