In 888, with the death of Emperor Charles the Fat, the empire of Charlemagne was permanently divided into four kingdoms: East Francia, West Francia, Kingdom of Burgundy, and the Kingdom of Italy with each of the four realms being ruled by their own kings. Though the Pope in Rome continued to appoint the kings of Italy as "Emperor" to rule Charlemagne's empire, these "Italian Emperors" never exercised any authority north of the Alps. With the assassination of Emperor Berengar I of Italy in 924, the last nominal heir to Charlemagne was dead and the title "Emperor" was left unclaimed.
King Rudolf II of Upper Burgundy, and Hugh, Count of Provence and effective ruler of Lower Burgundy, held competing claims to the vacant throne of Emperor in Italy. By 926, Hugh forced Rudolf to flee Italy, establishing de facto control over the Italian peninsula. Hugh later induced the Italian nobility to recognise his son Lothair II of Italy as their next king and crowned him in April 931. Hugh and Rudolf II eventually concluded a peace treaty in 933, with Rudolf II renouncing his claims to the Italian throne and Hugh granting control over Lower Burgundy to Rudolf II, which he combined with Upper Burgundy into a new Kingdom of Burgundy. To seal the peace, Rudolf II betrothed his infant daughter Adelaide to Hugh's son Lothair.
In 940, Margrave of Ivrea Berengar II, the grandson of former King Berengar I, led a revolt of Italian nobles against his uncle, Hugh. Forewarned by Lothair, Hugh exiled Berengar II from Italy and Berengar II fled to the protection of [King Otto of Germany]. In 945, Berengar II returned from exile in Germany and was welcomed by the Italian nobility. With the aid of hired mercenaries, Berengar II defeated Hugh in battle and forced him into permanent retirement in Provence. As part of the peace negotiations, Hugh was allowed to remain nominal king of Italy with Berengar II as the decisive power behind the throne. Lothair finally married the sixteen-year-old Adelaide on 16 December 947. When Hugh died on 10 April 948, his son Lothair succeeded him as nominal king, but Berengar II continued to hold all real power.
Lothair's brief "reign" came to an end with his death on 22 November 950, presumably poisoned by Berengar II, leaving Adelaide widowed before her twentieth birthday. Berengar II crowned himself king with his son Adalbert of Italy as his co-ruler and heir apparent. Failing to receive widespread support for his right to the crown, Berengar II attempted to legitimize his reign and tried to force Adelaide, the respective daughter, daughter-in-law and widow of the last three Italian kings, into marriage with Adalbert. Adelaide fiercely refused and was imprisoned by Berengar II at Garda Lake. With the help of Count Adalbert Atto of Canossa, she managed to escape from imprisonment. Besieged by Berengar II in Canossa, Adelaide sent an emissary across the Alps seeking Otto’s protection and marriage. Otto, widowed since 946, knew a marriage to Adelaide would allow him to fulfill his ambition of ruling Italy and, ultimately, claiming the imperial crown as Charlemagne’s true heir. Knowing of Adelaide’s great beauty and immense wealth, the thirty-eight-year-old Otto accepted nineteen-year-old queen's marriage proposal and prepared for an expedition into Italy.