The addition of hops to beer for bittering, preservation, and aroma is a relatively recent innovation: in the Middle Ages many other mixtures of herbs were often employed in beer prior to hops. These mixtures are often referred to as gruit. Hops were cultivated in France as early as the 800s; the oldest surviving written record of the use of hops in beer is in 1067 by well-known writer Abbess Hildegard of Bingen: "If one intends to make beer from oats, it is prepared with hops."