ADELAIDE (ADELHEID) (931-999), queen of Italy and empress, was the daughter of Rudolph H. of Burgundy, and married, in 947, Lothair, who succeeded his father Hugh as king of Italy. Lothair died in 950 and Adelaide was imprisoned at Como by his successor, Berengar H., marquis of Ivrea, who wished to compel her to marry his son Adalbert. After four months (August 951), she escaped, and took refuge at Canossa with Atto, count of Modena-Reggio. Meanwhile Otto I., the German king, whose English wife, Edgitha, had died in 946, came to Italy. Adelaide met him at Pavia, and at the close of the year the marriage took place. On Feb. 2, 962, she was crowned empress at Rome by Pope John XII. immediately after her husband, and she accompanied Otto in 966 on his third expedition to Italy, where she remained with him for six years.
After Otto L's death (May 7, 973), Adelaide exercised for some years a controlling influence over her son, the new emperor, Otto II. The causes of their subsequent estrangement are ob scure, but it was possibly due to the empress's lavish expenditure in charity and church building, which was a serious drain on the imperial finances. In 978 she left the court and lived partly in Italy, partly with her brother Conrad, king of Burgundy, by whose mediation she was ultimately reconciled to her son. In 983, shortly before his death, she was appointed his viceroy in Italy, and, in concert with the Empress Theophano, widow of Otto II., and Archbishop Willigis of Mainz, defended the right of her infant grandson, Otto III., to the German crown against the pretensions of Henry the Quarrelsome, duke of Bavaria.
In June 984 the infant king was handed over by Henry to the care of the two empresses; but the masterful will of Theo phano soon obtained the upper hand, and until the death of the Greek empress, on June 15, 991, Adelaide had no voice in German affairs. She assumed the regency, in concert with Archbishop Willigis and a council of princes of the Empire, and held it until in 995 Otto was declared of age. In 996 the young king went to Italy to receive the imperial crown; and from this date Adelaide devoted herself to pious exercises, to correspondence with the abbots Majolus and Odilo of Cluny, and to the founda tion of churches and religious houses. She died on Dec. 17, 999, and was buried in the convent of Saints Peter and Paul, her favourite foundation, at Salz in Alsace. By the Emperor Otto I. she had four children: Otto II. (d. 983), Mathilda, abbess of Quedlinburg (d. 999), Adelheid (Adelaide), abbess of Essen (d. 974) and Liutgard, who married Conrad IL, duke of Franconia, and died in 955.