sentences:  A Welsh language poem entitled "Armes Prydein", considered by Sir Ifor Williams to have been written in Deheubarth during Hywel's reign, called for the Welsh to join a confederation of all the non-English peoples of Britain and Ireland to fight the Saxons.The poem may be linked to the alliance of Norse and Celtic kingdoms which challenged Athelstan at the Battle of Brunanburh in 937.No Welsh forces joined this alliance, and this may well have been because of the influence of Hywel.