His son and successor, Conrad III, reigned more than fifty-six years from 937 to 993 and enjoyed the friendship and support of the Saxon emperors. Otto I married his sister Adelaide, who was the mother of Otto II, and the grandmother of Otto III. Conrad was succeeded by his son Rudolph III, surnamed "the Lossy". When Rudolph III died childless in 1032 without issue the sovereignty of the kingdom of Burgundy devolved as a fief or legacy to his nephew Conrad of Swabia, who was elected emperor in 1024. With Rudolph, this branch became extinct in the male line.