sentences:  To secure the Hohenstaufen rule, Conrad had the princes elect his son Henry Berengar, then ten years old, as co-King of Germany at an Imperial diet held in Regensburg on 13 March 1147.Overall King Conrad relied in a great extent to the relatives of his wife Gertrude for support.Gertrude died in 1146 at Hersfeld Abbey, as she became ill after the birth of her second son Frederick.