ROTHAY (The), a river of Westmoreland; rising at Dunmail-Raise; and running about 8 miles south-east-ward, through Grasmere lake and Rydal water, to the river Brathay a few yards above the latter's influx to Windermere. The scenery of its basin comprises all Helm-Crag, Easdale, Grasmere, and Rydal, together with the encircling mountains; and is richly picturesque.

(John Marius Wilson, Imperial Gazetteer of England and Wales (1870-72))