The beauty of nature, the horror of man

It was hot and very humid and flies buzzed around the hay
In the open space behind, men fraught a bloody war that day
The river meandered from the hills, as it found it's way on down
And the crash of armour and screams of pain could be heard all around
Then the battle reached a climax with thousands dying on the ground
The king lay beside a tree, with bloody sword hole from face to brain
A waste of humanity around him, never to raise an army again
Now amongst the dead and dying, there begins a summer rain