 The only certain historical knowledge about the bandits is that they murdered the Sheriff of Meirionnydd, the Baron Lewis ap Owen, of Cwrt Plas-yn-dre, Dolgellau on 12 October 1555.The attack was carried out by a group of bandits in Dugoed Mawddwy, near Dinas Mawddwy.Several of the bandits were hanged for the murder, and there are laments for the Baron by a number of poets, including Gruffudd Hiraethog.