In this book
I just have finished reading an account of Bin Qasim's invasion of India
(actually, Sind, in present day Pakistan.)
The following passage is interesting:
And King Dahar never understood the nature of the war
...
There was for him, in war, an element of chivalry and deadly play.
He could have prevented Bin Qasim from crossing the Indus River;
it was what he was advised to do.
But he thought that undignified.
He could have retreated even then,
and left the desert to deal with the invaders;
it was again what he was advised to do.
But again he thought that undignified.
He died in battle.