Like several other oriental fruit trees, bitter orange was brought back by the soldiers of Alexander to their respective countries and, fifteen centuries later, reintroduced by the crusades to a Western world that had largely forgotten it. Its fruit, the bitter orange, was known to our ancestors long before it was cultivated. They justifiably praised its peel, that they used as a digestive tonic, serving it as an entrée to their copious feasts and protecting them from the consequences of over-indulgence. The Greek Theophrastus, founding father of botany thanks to his treatises Enquiry into plants and On the causes of plants, praised the virtues of this fruit as early as the 4th century BC. Six centuries later, Galienus, physician to the emperor Commodus, prescribed it for a great many ailments. In Chinese traditional medicine, it is used to treat digestive and cardiac disorders: zhi shi (unripe fruit) and zhi kiao (rind). Combining sweetness with bitterness, this exquisite and paradoxical fruit inevitably inspired poets. Thus, Aragon sang his ”sombre amour d’orange amère” (dark lover for bitter orange).