One who changed the flow

Rædwald of East Anglia was prepared
For the battle across the River Idle
His troops were no different in armor or weapons
Than any of the enemy
But they were superior
None should compare
The rivals
Only that  one will rise when threatened
And the other would fulfill a different destiny
Rædwald was the final spear carrier
And his reign would deny fate
For his way changed his land
And his life was remembered
As achieving greatness