A contemporaneous, though not an eyewitness, account was given by Giraldus Cambrensis in his De principis instructione ("Instruction of a Prince", c. 1193) and recollected in his Speculum Ecclesiae, c. 1216 according to which the abbot, Henry de Sully, commissioned a search, discovering at the depth of 16 feet a massive hollowed oak trunk containing two skeletons.