The Lithaha River in the Carolingian Avar March was first mentioned in an 833 deed issued by Louis the German, son of the Carolingian emperor Louis the Pious and ruler over the stem duchy of Bavaria. The Old High German name lît probably referred to a Pannonian (Illyrian) denotation for "mud", as maintained in the former Hungarian name Sár (cf. mocsár: swamp).