He became King of The Germans (Emperor Elect) in 1026, Duke of Bavaria in 1027, Duke of Schwaben in 1038, and Emperor in 1039. He resolutely maintained the imperial prerogatives of power and encouraged the efforts of the Cluniac monks to reform the ecclesiastical system of Europe. 
In 1046 he put an end to the intrigues of the three rival popes by deposing all three and electing Clement II in their stead. In 1042 he compelled the Duke of Bohemia to acknowledge himself a vassal of the empire. By repeated campaigns in Hungary, he established the supremacy of the empire in 1044. 
Heinrich III also stretched his authority over the Norman conquerors of Apulia and Calabria. He promoted learning and the arts, founded numerous monastic schools and built many great churches. 
 

Source: Leo van de Pas