I am always on the look out for great websites with useful resources for game masters. Usually I find them through blind luck or referral. In this case, I found this site through an odd source…the Economist last week! Amazing what you can find in a business magazine these days. Regardless, warscholar.com is a great resource for anyone doing research on warfare. Though geared towards re-enactors, it has a great collection of military equipment links and you can never have enough equipment in a campaign. Links aside, I am very fond of the detailed warfare time line. It graphically represents wars throughout recorded history in an easy to read format. It is also helpfully sorted by year and region. Invaluable for dredging up an obscure conflict in an historical RPG or for use as an inspiration in just about any RPG setting. Here is a screen shot of the timeline for 1200-1224.
Trask, The Last Tyromancer