In the dispute between Philip of Spanheim, who had been elected as Archbishop of Salzburg, and Count Meinhard I of Gorizia and Tyrol, Henry and his brother Bernard initially sided with Philip of Spanheim, in order to protect their fiefs in Carinthia, Styria and Salzburg.
A deed of their alliance has survived, which was sealed on 1 June 1250 in Fohnsdorf; a number of vassals of the Pfannbergs are named as guarantors.
Henry was bribed by King Bela IV of Hungary, who attempted to make his son Duke of Styria.
In 1260, Henry married Agnes of Plain-Hardegg, the daughter (or sister) of Count Conrad III (1230-1260).
Agnes is last mentioned in a record dated 10 April 1298 in Ehrenhausen, when she donated her dower, namely Loschental Castle in the Lavant Valley and the tower in Lavamünd with all appurtenances, to the Archbishopric of Salzburg, in return for the archbishop praying for the salvation of her soul.