Timeline of Germ Warfare

Oct. 5 -- Biological and chemical warfare are generally associated with the technological advances that created modern warfare in the 20th century. But the use of poison and disease in war, against soldiers and citizens alike, dates back much further, even before the discovery of bacteria in the 17th century and germs in the 19th century.

1346: During the siege of Kaffa, a Genoese port on the Crimean peninsula in the Black Sea, the attacking Tartars are devastated by an outbreak of the plague. They are forced to abandon the siege, but before leaving they use catapults to hurl the plague-infested bodies of their dead comrades over the walls of the city. The plague spreads through the city, whose fleeing residents then take it to Italy. The second outbreak of "black death" in Europe can be partly blamed on biological warfare.

1518: In Latin America, Spanish conquistador Hernando Cortes exposes the Aztec to smallpox, which soon devastates the native population, paving the way for Cortes' complete victory in 1521. In the 1530s, a similar smallpox epidemic spreads throughout the Incan civilization as a result of the arrival of the Spanish.

1675: After learning to grind lenses, Dutch scientist and tradesman Anthony Leeuwenhoek makes simple microscopes, and becomes the first human to see bacteria.

1710: During the war between Russia and Sweden, Russian troops are said to use the cadavers of plague victims to provoke an epidemic among the enemy.

1767: During the French and Indian War in North America, an English general, Sir Jeffery Amherst, gives blankets infected with smallpox to Indians who are helping the French defend Fort Carillon. The English had twice attacked Fort Carillon and both times were repulsed with heavy losses. But the smallpox ploy works, causing an epidemic that decimates the Indians and allows Amherst to capture the fort and rename it Fort Ticonderoga.

1855: Louis Pasteur, the father of microbiology, begins working with yeast, eventually proving it is made up of living organisms. His work uncovers the existence of germs and their disease capabilities.