just finished reading a book online about khalid, the pivotal general during the expansion of early islam into iraq and syria. the book is about his campaigns and gives relatively good backgrounds for the campaigns, battles and opposing forces. it is really good at giving the characters a humanistic feel. khalid, his arch rival the second caliph Umar, and even Mohammed come across as real people with personalities and traits, something that is usually not done with iconic historical figures, especially those with a religious significance.

now the book is written romantically. heroic figures dash about the battlefield, and the opposing generals always seem to end up dueling, but from what i know, most of the underlying facts are sound.

http://www.swordofallah.com