Otto’s son Liudolph, from his stronghold in Swabia located just north of the Alps, is in closer proximity to the Italian border than his father in Saxony.
Liudolf prepares an Italian campaign is to overthrow Berengar II and therefore render unnecessary Otto's own expedition into Italy, and thus his marriage to Adelaide.
While the exact reason for Liudolf's actions are unclear, dynastic concerns and family ties to Adelaide may have been a factor.
Adelaide's mother, Bertha of Swabia, was a daughter of Regelinda, the mother of Liudolf's wife Ida, from her first marriage to Burchard II, Duke of Swabia.
Liudolf, therefore, may have intervened in the Italian campaign at the request of Adelaide's relatives.
Additionally, Liudolf, nineteen years old himself, does not view the idea of a young stepmother as in his best interests.
Though Otto had named him as his successor, Liudolf fears any potential stepbrother may usurp his claim to the German throne.
While Liudolf is preparing his expedition, the Bavarian Duke Henry, Otto's brother and Liudolf's uncle, conspires against him; Swabia and Bavaria share a long common border and the two dukes are involved in a border dispute.
Henry influences the Italian aristocrats not to join Liudolf's campaign.
Therefore, when Liudolf arrives in Lombardy in early summer 951, he finds no support and is unable to sustain his troops.
His army is near destruction until Otto's own army crosses the Alps.
The King reluctantly receives Liudolf's forces into his command, angry at his son for his inconsiderate and independent actions.
Otto and Liudolf arrive n northern Italy in September 951 without opposition from Berengar II.
As they descend into the Po River valley, the Italian nobles and clergy withdraw their support for Berengar and provide aid to Otto and his advancing army.
Recognizing his weakened position, Berengar II flees from his capital in Pavia.
When Otto arrives at Pavia on September 23, 951, the city willingly opens its gate to the German king.
In accordance with Lombard tradition, Otto is crowned with the Iron Crown of the Lombards on October 10.
Like Charlemagne before him, Otto is now concurrent King of Germany and King of Italy.
Otto sends a message to his brother Henry in Bavaria to escort his bride from Canossa to Pavia, where the two marry.
Soon after his father's marriage, Liudolf leaves Italy and returns to Swabia.
