Daughter of Rudolf II of Burgundy, she was married to Lothair, king of Italy. After Lothair died in 950 -- perhaps poisoned by Berengar II who seized the thone or his son -- she was taken prisoner in 951 by Berengar II who wanted her to marry his son.
Otto I "the Great" of Saxony rescued Adelaide and defeated Berengar, declared himself king of Italy, and then married Adelaide. (His first wife was Edith, daughter of Edward the Elder.) When he was crowned as Holy Roman Emperor on February 2, 962, Adelaide was crowned as empress. She turned to religious activity, promoting monasticism. Together they had five children.
In 996, Otto III was finally crowned at Rome, and Adelaide focused on the religious life, founding more churches, convents and monasteries. She retired to a convent where she died in 999.