In this millennium the Tartars had similar ideas, throwing the bodies of plague victims over the walls of cities under siege. They used it in Crimea in 1346 against the Genoese, spreading the black death to Italy.
The British copied the strategem in about 1760 when Sir Jeffrey Amherst, the British Commander-in-Chief in North America, battling to contain the American Indians, asked a subordinate, "Could it not be contrived to send the smallpox among these disaffected tribes?" Two hostile Indian chiefs were duly presented with a gift of blankets and a handkerchief retrieved from a smallpox hospital.
Humanity's fascination with biological warfare was honed by the wars of the 20th century. British interest grew strongly from 1934 onwards, but it wasn't until 1940 that a secret biological warfare laboratory was set up at Porton Down. Anthrax bombs were successfully tested against sheep over the Scottish Island of Gruinard in 1941 and 1942, contaminating the island for decades, and in a note to General Sir Hastings Ismay in May 1944, Churchill referred to an order for half a million anthrax bombs. In the event the war ended without such a weapon being ready. The only anthrax weapons left in Brtain's stockpiles in 1945 were five million infected cattle cakes for use against German livestock.
The Japanese did extensive research on biological weapons before and during the Second World War, ending up with far larger stocks than any other nation. The notorious Unit 731 based in northern Manchuria killed some 3,000 human guinea pigs in biological weapons experiments, most of the victims being Chinese and Russian POWs. In 1942 Japanese forces used the biological weapons they'd developed against the Chinese in the Chekiang Campaign, causing "inestimable" losses.
Surprisingly, after the Japanese surrender, the United States did a deal with the Japanese scientists involved, giving them immunity from prosecution for their war crimes in exchange for research data. The great value of this data was described in a report written in 1947 by Dr Edward Hill, scientific chief at America's own BW research centre at Camp (later Fort) Detrick. "Such information could not be obtained in our own laboratories," he wrote, "because of scruples attached to human experimentation."
In the 1950s, Britain and America continued their experiments into the most efficient and lethal methods of releasing bacterial material from bombs and airborne sprays. Britain abandoned its development programme in 1957, but America continued work on offensive weapons until the programme was stopped by President Nixon.
Efforts to contain the nastier aspects of warfare started in the last century with the St Petersburg Declaration of 1868, but it wasn't until 1972 that a specific Biological and Toxic Weapons Convention was agreed, banning the production of such weapons except in quantities sufficient to develop defences against them. Despite being a key player in this agreement, the Soviet Union carried on producing biological weapons in secret until 1992.
Today the danger from biological weapons may no longer stem from major national development programmes. History may have come full circle, in fact, back to a modern-day equivalent of the ancient Greeks poisoning drinking water. Intelligence agencies fear that the greatest risk now is from terrorists or fanatics releasing small quantities of these easy- to-produce germs in places like the underground railways of major cities.
Geoffrey Archer is the author of `Fire Hawk' (Century, pounds 10)