In A Nutshell
Use of and the threat of chemical agents used in modern warfare have sent governments worldwide scrambling for a way to regulate the use and possibility of chemical warfare. It’s not a new idea, however, and archaeologists have found evidence that the idea of using poison gas as a weapon dates to about A.D. 256, when it was first used in what is now Syria.
The Whole Bushel
The use of poison gas was outlawed with the Geneva Protocol in 1925, and it turns out that it took mankind almost 17 centuries to do it.
The first evidence of chemical warfare comes from an area of Roman-controlled Syria in the year A.D. 256 and it was engineered by the Persians. The city of Dura-Europos was situated on the Euphrates River, and was a Roman sanctuary surrounded by the Persian Empire. This obviously didn’t sit well with the Persians, who laid siege to the Roman city in an attempt to recover control.
One of the methods used was the construction of tunnels beneath the Roman walls. The Romans also began digging their own tunnels in order to counter their attackers, but the Persians had the upper hand. It’s thought that they heard the movements of the Romans and could judge where they were going to be, so they prepared a deadly mixture of sulfur and bitumen. Once ignited, the burning chemicals would fill the tunnels with a deadly gas, probably helped along from Persians safely outside and armed with bellows. (That’s still an unconfirmed part of the excavation, and with no written records to tell exactly what happened inside and outside the walls, it’s unlikely to be anything but conjecture.) What is known, though, is that with the Persian tunnel lying below the Roman one, a naturally-formed chimney effect was likely to have also helped the process along.
And what they set out to do is exactly what they did. Excavations have uncovered piles of Roman bodies, still clad in armor, still in the tunnels where they died. There was also the discovery of a single Persian warrior, laying apart from the others, who had most likely been the one to set the fires in the first place and become one of the first victims to the deadly gas.
The Romans themselves were known for using strategically placed piles of gypsum powder near the entrances to enemy tunnels and outside enemy walls, rendering the air un-breatheable with a good gust of wind. Similar techniques were used by the Chinese in A.D. 178, with limestone-filled chariots instead of piles of gypsum; the result of the circling chariots was dust-filled air that was even more potent than modern tear gas. These early predecessors to chemical warfare set the tone and sparked ideas.
In 1346, the Crimean city of Caffa was brought to its knees when disease-ridden corpses were hurled over their walls by catapults manned by besieging Tartars. The corpses were bodies of those that had been killed by the plague, introducing it to the city in early germ warfare.
Although it took until 1925 for chemical warfare to be outlawed in modern warfare, the Geneva Protocol isn’t the first time people have come together to agree that chemical warfare is less than noble. A Hindu code of laws dating from the fifth century B.C. outlaws the use of poison arrows, and an Indian treatise written in the fourth century B.C. outlined procedures for creating deadly gases and toxins. It also warned against their use, however, stating very clearly that they were only a last resort and there were better ways to win a battle.