Conrad III (1093-1152), the first German king of the Hohenstaufen dynasty, was the son of Frederick I, Duke of Swabia. As duke of Franconia, he supported the unsuccessful candidacy of his brother, Frederick II of Swabia, for the kingship of Germany on the death of the Holy Roman Emperor Henry V (1125).

Elected king of Italy in December 1127 in opposition to Lothar II, Conrad acknowledged Lothar as emperor only in 1135. After Lothar's death (December 1137), Conrad was elected king of the Romans (the title customarily accorded preparatory to accession as emperor) and thereby ruler of Germany at Coblenz in March 1138.

In 1146, Conrad heard Bernard of Clairvaux preach the crusade at Speyer, and he agreed to join Louis VII on the Second Crusade. Conrad and his army went overland, via Hungary, causing disruptions throughout the Byzantine territories they crossed through. They arrived at Constantinople by December of 1146, ahead of the French army.

Rather than take the coastal road around Anatolia through Christian-held territory, by which he sent most of his noncombatants, Conrad took his army straight across Anatolia. On October 25, 1147, they lost a major battle to the Turks at Dorylaeum. Conrad and most of the mounted knights escaped, but most of the foot soldiers were killed or captured. Conrad later reached the crusader kingdom by sea from Constantinople.

Conrad was never crowned emperor, and continued to style himself king of the Romans until his death. He designated his nephew Frederick I Barbarossa his successor, rather than his own son - showing that lineal descent of offices had not yet overtaken earlier ideas of family succession.