Brewing and seafaring are mainstays of ancient human endeavors. Beer was first fermented by at least the 5th millennium BC in Mesopotamia. From the land between the Tigris and Euphrates Rivers of the Fertile Crescent, the grain beverage either traveled along trade routes or was spontaneously developed in other ancient civilizations (including Egyptian, Grecian, Roman, Norse, Aztec, Chinese) before landing in northern Europe in the early medieval period. Producing beer became a standard domestic chore in households, and later, on a slightly larger scale, in taverns and monasteries.