Something Awful has just put up a long post:
Ancient Superweapons F*****g Rock (my stars, not theirs).
This illustration depicts a Byzantine Greek invention called 'Greek Fire' - and comes from a 12th century codex of Ioannes Skylitzes' Synopsis of Histories - covering the 9th to 11th centuries.
For more information, a short history of Incendiary Weapons in warfare can be found here. The recipe is alas now lost, so we can't test it, but 'Greek Fire' seems to have been a Byzantine invention. It could also be used in small shells, a bit like grenades.
Adrienne Mayor has written about it most recently (intro to her book here).
Another great source for Byzantine and Crusader warfare is The Alexiad of Anna Komnene.
Anna was for a long time brother-less, and had assumed that she would inherit the throne; history didn't work out that way, as first a younger brother was born (1087), and then he inherited the empire and became John II Komnenos (1118 - see the mosaic depicting him from Haghia Sophia in my photo).
She conspired against him several times, until she was forced into exile at a nunnery. There, having been forbidden poems in her youth, least they led her to be lustful, she turned to writing history and produced The Alexiad, a chronicle of her father Alexius I's reign and of his involvement in the First Crusade. Her husband, Nikephoros Bryennios, had been a general in the Holy Land and the assumption is that she derived much of her information concerning military strategy from him. It is available in translation here.