(also known as Lothair the Saxon, Lothair of Supplinburg, or Lothair II). Born circa 1075; died Dec. 3, 1137, in Breitenwang am Lech. German king (from 1125); emperor of the Holy Roman Empire (from 1133).
Lothair, a Saxon duke (from 1106) and count of Supplinburg, was the most powerful of the North German princes. He led their revolt against the attempts of Henry V to strengthen royal power. After the death of Henry V, he was elevated to the throne with the support of ecclesiastical feudal lords, as a consequence of which their influence significantly increased during the reign of Lothair III. He carried out two campaigns (1132-33 and 1136-37) against Italy. In 1134 he enfeoffed the North Mark to Albert the Bear.