The Devout Man and the Rotting Skull

I heard that once, in a town called Hilla, a skull spoke with a devout man. It said: I once held the glory of command; on my head I wore a crown of power. Fortune backed me, victory and harmony were mine; with the strength of Iraq I seized my prize. I had set my greed on devouring Kerman, when suddenly the worms devoured my head. Pull the cotton of heedlessness from the ear of your mind, so that the dead may bring their lesson to your ears.