Ancient Persians used chemical weapons first

Weapons of mass destruction have been around for a lot longer than anyone thought. A British archaeologist has found evidence that ancient Persians used chemical warfare in a siege against a Roman garrison more than 18 centuries ago. Dr. Simon James was looking for an explanation of a curious discovery 70 years ago during excavations an old Roman outpost in Syria—the bodies of 20 Roman legionnaires, in full armour stacked neatly in what had been a narrow tunnel under the battle site. 

Telegraph.co.uk