The king again employed Ealdred as a diplomat in 1056, when he assisted Earls Harold and Leofric in negotiations with the Welsh. Edward sent Ealdred after the death in battle of Bishop Leofgar of Hereford, who had attacked Gruffydd ap Llywelyn after encouragement from the king. However, Leofgar lost the battle and his life, and Edward had to sue for peace. Although details of the negotiations are lacking, Gruffydd ap Llywelyn swore loyalty to King Edward, but the oath may not have had any obligations on Gruffydd's part to Edward. The exact terms of the submission are not known in total, but Gruffydd was not required to assist Edward in war nor attend Edward's court. Ealdred was rewarded with the administration of the see of Hereford, which he held until 1061, and was appointed Archbishop of York. The diocese had suffered a serious raid from the Welsh in 1055, and during his administration, Ealdred continued the rebuilding of the cathedral church as well as securing the cathedral chapter's rights. Ealdred was granted the administration in order that the area might have someone with experience with the Welsh in charge.