(born early June 1075 — died Dec. 3/4, 1137, Breitenwang) German king (1125 – 37) and Holy Roman emperor (1133 – 37). The most powerful noble in Saxony, he took part in revolts (1112 – 15) against the German king Henry V. Elected king on Henry's death, he fought a war against the
Hohenstaufen who claimed the throne (1125 – 29); his victory was a triumph for elective monarchy over hereditary succession. Lothar was crowned emperor as a reward for supporting Pope Innocent II (1133). He made peace with the Hohenstaufen (1135) but attacked
Roger II of Sicily, driving him out of southern Italy (1136 – 37).
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