A striking and famous feature of the English landscape, Dartmoor (in the southwest of the country) is a beautiful place, with a sense of wildness and mystery. But in the Middle Ages intensive practical use was made of its resources: its extensive moorlands provided summer pasture for thousands of cattle from the Devon lowlands, which flowed in a seasonal tide, up in the spring and down in the autumn.  This book describes, for the first time, the social organization and farming practices associated with that annual transfer of livestock. It presents evidence for a previously unsuspected Anglo-Saxon period of transhumance, by which the cattle's lowland owners moved with their animals and lived temporarily on the moor every summer.