An ancient empire that clashed with Babylon and Egypt spread terror using sick sheep, an Italian researcher believes.
Until now, the Hittites of Anatolia - modern-day Turkey - were celebrated in the annals of warfare for their fearsome skill with the chariot.
But many of their conquests can also be ascribed to their ruthless use of diseased sheep, researcher Siro Trevisanato says.
''The Hittites were the first people to wage bioterrorism,'' he claims in the Journal of Medical Hypotheses.
Trevisanato spent years poring over ancient accounts of Hittite conquests in the 14th century BC.
He came to the conclusion that the warrior people used Tularemia, an animal-borne infection that is fatal to humans, to aid their campaigns of expansion.
In 1325 BC, for example, the Hittites sacked the Phoenician city of Symra, on the borders of modern-day Lebanon and Syria.
''It is then that we first hear of the so-called Hittite Plague. It appears in several documents. It is no accident, in my view, that it coincides with the first documented appearance of Tularemia''.
The Hittites also used Tularemia-carrying sheep as a defensive weapon, Trevisanato thinks.
''At a weak point in their history the Hittites came under attack from a neighbouring people from the city of Arzawa,'' he says.
''It was in those same years that sheep started mysteriously appearing in the streets of Arzawa. The inhabitants captured them and ate them.
''Tularemia started reaping victims in the city and the conquest of the Hittites failed''.
Trevisanato has found documents in which the bewildered Arzawans wonder whether there is a connection between the sheep and the epidemic that has weakened their ranks.
He thinks there can be no doubt on that score.
''These diseased sheep were the world's first weapons of mass destruction''.
