Liudolf (930 ? 6 September 957) was the duke of Swabia from 950 until 954. He was the only son of Otto I, king of Germany, by his wife Eadgyth, daughter of Edward the Elder, king of England.
Liudolf married Ida, daughter of Duke Herman I. When Herman died, Otto appointed his eldest son and heir apparent duke. Liudolf was a popular ruler with the tribe. After the usurpation of Berengar II of Italy, he invaded Lombardy in 951. His father foiled his plans and invaded as well, leaving Liudolf without much gain. When Otto married Adelaide, the heiress to Italy, Liudolf felt his position threatened and raised the flag of revolt in 953. Though he had the support of his Swabians, his ally (and brother-in-law), Conrad the Red, was opposed by his own subjects in Lorraine. The Bavarians of Henry I, Duke of Bavaria, Liudolf's uncle, supported Liudolf, but Henry and Otto together put down the rebellion. In 954, he was deprived of his duchy and, though reconciled with his father, he did not regain it. He invaded Italy for a second time in 957 and many cities capitulated before him and Berengar fled. He died unexpectedly of fever amidst his victorious campaign at Pombia, near Novara, on September 6 and was buried in St. Alban's Abbey, Mainz.
His son by Ida, Otto, was later duke of Bavaria and Swabia, his daughter Mathilde, abbess of the Essen Abbey. He also founded the city of Stuttgart in southern Germany (wikipedia)