Between 1013 and 1016 Bishop Athelstan was consecrated Bishop of Hereford.
John of Worcester. 1055. On receiving intelligence of this calamity, the king immediately commanded an army to be levied from every part of England, and on its being assembled at Gloucester, gave the command of it to the brave earl Harold (age 33), who, zealously obeying the king's orders, was unwearied in his pursuit of Griffyth and Algar, and boldly crossing the Welsh border, encamped beyond Straddell [Snowdon]; but they knowing him to be an intrepid and daring warrior, did not venture to wait his attack, but retreated into South Wales. On learning this, he left there the greatest part of his army, with orders to make a stout resistance to the enemy if circumstances should require it; and returning with the remainder of his host to Hereford, he surrounded it with a wide and deep trench, and fortified it with gates and bars. Meanwhile, after an interchange of messages, Griffyth, Algar, and Harold (age 33), with their attendants, met at a place called Biligesteagea, and peace being proposed and accepted, they contracted a firm alliance with each other. After these events, earl Algar's fleet [of pirates] sailed to Chester [Map], and waited there for the hire he had engaged to pay them; but he himself went to court and restored by the king to his earldom. At that time died Tremerin, a Welsh bishop,[Bishop of St Davids] who had been a monk. He was, for a long time, coadjutor to Athelstan, bishop of Hereford, after Athelstan became incapable of performing his episcopal functions, having been blind for thirteen years. Heriman, bishop of Wiltshire, being offended at the king's refusing to allow him to remove the seat of his bishopric from the vill called Ramsbury to the abbey of Malmesbury, resigned his bishopric and, going beyond sea, took the monastic habit at St. Bertin, [an abbey near St Omer] in which monastery he abode for three years.
Flowers of History 1056. 1056. Ethelstan bishop of Hereford died, and was succeeded by Levegar, duke Harold's chaplain. This prelate, who was a model of piety, was slain by Griffin king of Wales, who burnt the city of Hereford. Levegar was succeeded by Walter who continued to the time of King William. In the same year Egelric bishop of Durham voluntarily left his bishopric, and took the monastic habit at Peterborough, where he lived an exemplary life twelve years.
On 10 Feb 1056 Bishop Athelstan died. He had been blind for thirteen years.
John of Worcester. 16 Jun 1056. Athelstan, bishop of Hereford, a man of great sanctity, died on the fourth of the ides [the 10th] of February, at the episcopal vill called Bosanbyrig [Bosbury]; his body was carried to Hereford, and buried in the church [Map] which he himself had built from the foundations. He was succeeded by Leovegar, earl Harold's chaplain, who, on the sixteenth of the calends [the 16th] of June in the same year, together with his clerks and Ethelnoth the vice-reeve and many others, was massacred by Griffyth, king of Wales, at a place called Claftbyrig [Map]. He held the see only eleven weeks and four days. On his being thus cut off, the bishopric of Hereford was administered by Aldred, bishop of Worcester, until a successor could be appointed. This same bishop Aldred and the earls Leofric and Harold (age 34) afterwards reconciled Griffyth, king of Wales, with king Edward.