 Afterwards, however, the subsequent Merfynion dynasty established its northern court at Aberffraw on the opposite side of the island instead.A wooden fortresssquare with a round tower at each anglewas constructed at the site by the Normans Hugh the Wolf of Chester and Hugh the Red of Shrewsbury during their 1098 invasion.During the Battle of Anglesey Sound between the Two Hughs and King Magnus Barefoot of Norway, Magnus was said to have personally shot Hugh the Red through the eye with an arrow before discovering whom he was fighting and withdrawing back to the north.