While Ug99 wasn't discovered until 1999, stem rust has been an ongoing problem dating back to Aristotle's time (384-322 B.C). An early ancient practice by the Romans was one where they would sacrifice red animals such as foxes, dogs, and cows to Robigus ("fem." Robigo), the rust god. They would perform this ritual in the spring during a festival known as the Robigalia in hopes of the wheat crop being spared from the destruction caused by the rust. Weather records from that time have been reexamined and it has been speculated that the fall of the Roman Empire was due to a string of rainy seasons in which the rust would have been more harsh, resulting in reduced wheat harvests. Laws banning barberry were established in 1660 in Rouen, France. This was due to the fact that European farmers noticed a correlation between barberry and stem rust epidemics in wheat. The law banned the planting of barberry near wheat fields and was the first of its kind.