In pre-Christian times, horse meat was eaten in northern Europe as part of Teutonic religious ceremonies, particularly those associated with the worship of Odin. Europe was also periodically invaded by horse-eating Asian nomads like the Huns and Mongols, whose descendants continued the diet. The eating of horse meat is forbidden by Jewish and some Christian religions. In AD 732, Pope Gregory III tried to stop the pagan practice of horse eating, calling it "abominable". In some countries the effects of this prohibition by the Catholic Church have lingered, and horse meat prejudices have progressed from taboos to abhorrence. According to legend, the French taste for horse meat dates from the Battle of Eylau in 1807, when the surgeon-in-chief of Napoleon's Grand Army, Baron Dominique-Jean Larrey, advised the starving troops to eat the flesh of dead battlefield horses. The cavalry used breastplates as cooking pans and gunpowder as seasoning, and thus founded a tradition. Today many European countries including France, Italy, Romania, the Netherlands, Spain, Portugal and Belgium consume horse meat in notable volumes. China is actually the largest producer of horse meat.