The diary is actually a small notebook wherein one educated soldier (he
could read and write, obviously) kept a memoir of his days in the Sultan's
service.  The first half of the book has been ruined by weather and age, 
but the last half is readable and contains much information.
  Apparently the Sultan's rule was iron-fisted and harsh, and his counsel
of advisors was made up of a group called The Circle of Fire.  Many years
did the Sultan rule over this entire wasteland until his keep, which the
soldier refers to as 'Scorch Keep,' was attacked by an army of do-gooders
who sought to wipe out the Circle's power and slay the Sultan for crimes
against the nations to the north which he had threatened.  Apparently
the attack was successful and the Keep overthrown, because the soldier's
last entry details his fellows readying to go forth and repell a fresh
attack by the invaders.  He never wrote another word in this book.