First, it was the
Mongols under
Genghis Khan that invented the first form of
biological warfare, by tossing dead, decaying bodies over castle walls, in the hopes that whatever
disease the body might have (not to mention that a decaying body was probably disgusting and sickening enough - even if the person was healthy) would spread to the
sieged people inside. Though, in
Italy, angry people whom had contracted the plague, began hurtling the bodies onto ships, over walls, trying to get at the people whom they'd thought that had infected them.
Plague generally refers to the bubonic plague, also refered to as the "black plague."
The plague is transmitted by the rat flea (Xenopsylla Cheopis). The flea receives the bacteria from the rat; it then spreads it to humans. The bacillus Yersinia Pestis infects the lymph nodes, spreading buboes to the typical rash places, groin, armpits, neck. Other early symptoms includes a fever between 101 and 105 degrees Fahrenheit, nausea, painful joint areas, and vomiting.
The plague makes a person severely lethargic, and purple to black blotches appear all over the skin (thus, the black plague). Death comes quickly - about a week in a strong, healthy person. Easily trasmitted (through both the rats and fleas), it spread quickly throughout European history, killing millions over a span of about three to six years.
Additional Info: the plague, Exotic Weapons, siege
To read an interesting article on the Church's involvement in the plague, feel free to go to http://www.ecnet.net/users/gemedia3/Plague/Plague.html