Earl or Mormaer of Strathearn is a title of Scottish nobility, referring to the region of Strathearn in southern Perthshire. Of unknown origin, the mormaers are attested for the first time in a document perhaps dating to 1115. The first known mormaer, Malise I, is mentioned by Ailred of Rievaulx as leading native Scots in the company of King David at the Battle of the Standard, 1138. The last ruler of the Strathearn line was Malise, also Earl of Caithness and Orkney, who had his earldom forfeited by King Edward Balliol. In 1344 it was regranted by King David to Maurice de Moravia, a royal favourite who had a vague claim to the earldom as Malise's nephew and also stepfather.