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.
There is only one verified historical record of the gang's activities, which involved the murder of Sheriff Baron Lewis ap Owen of Cwrt Plas-yn-dre in Dolgellau on 12 October 1555. The assault was carried out by a group of thieves in Dugoed Mawddwy.