Holinshed's Chronicle 1175 is in Holinshed's Chronicle.
The same yeare [1175] William de Breause having got a great number of Welshmen into the castell of Abergauennie [Map], vnder a colourable pretext of communication, proponed this ordinance to be receiued of them with a corporall oth; That no traueller by the waie amongst them should beare The Welshmē not well dealt withall.any bow, or other vnlawfull weapon. Which oth when they refused to take, bicause they would not stand to that ordinance he condemned them all to death. This deceit he vsed towards them in reuenge of the death of his vncle Henrie of Hereford, whom vpon easter euen before, they had through treason murthered, and were now acquited with the like againe.