In the royal election of 1125, he supported his son-in-law Frederick II, Duke of Swabia , but switched his allegiance to Lothair, Duke of Saxony , after Lothair promised that Gertrud, his only daughter and heir, would marry Henry's son Henry .  After Lothair won the election and banned Frederick, in 1126 Henry abdicated as duke of Bavaria and retired to the family foundation of Weingarten Abbey so that he did not have to take part in the prosecution of his son-in-law. Henry died shortly thereafter and was buried in Weingarten.