The main source of information about the battle is the praise-poem "Battle of Brunanburh" in the "Anglo-Saxon Chronicle". After travelling north through Mercia, Æthelstan, his brother Edmund, and the combined Saxon army from Wessex and Mercia met the invading armies and attacked them. In a battle that lasted all day, the Saxons fought the invaders and finally forced them to break up and flee. There was probably a prolonged period of hard fighting before the invaders were finally defeated. According to the poem, the Saxons "split the shield-wall" and "hewed battle shields with the remnants of hammers ... here lay many a warrior by spears destroyed; Northern men shot over shield, likewise Scottish as well, weary, war sated". Wood states that all large battles were described in this manner, so the description in the poem is not unique to Brunanburh.