Lothair III was a significant figure in medieval Europe, serving as the Holy Roman Emperor from 1133 until his death in 1137. Born in 1075, he was a member of the Salian dynasty and became king of Germany in 1125. His reign was marked by efforts to strengthen the authority of the emperor and to manage conflicts with the papacy and various German princes. During his rule, Lothair III faced challenges, including the ongoing struggle for power with the Hohenstaufen family, particularly Conrad III. He participated in the Second Crusade but returned to Europe without achieving significant success. Lothair's reign laid the groundwork for future conflicts in the Holy Roman Empire.