Lothair III was a Holy Roman Emperor who reigned from 1133 to 1137. He was born in 1075 and belonged to the Salian dynasty. Lothair was known for his efforts to strengthen the authority of the emperor and to maintain peace among the various German princes during a time of political fragmentation. During his reign, Lothair III faced challenges from rival factions, including the Welfs and the Hohenstaufen. He played a significant role in the Investiture Controversy, a conflict between the papacy and secular rulers over the appointment of church officials. Lothair's reign ended with his death in 1137, after which he was succeeded by Conrad III.