His father died in 1220, nevertheless he did not come in control over all his family's possessions around Lienz and Gorizia upon the death of his uncle Count Meinhard the Elder.

About 1237 he married Adelaide (Adelheid), one of the two daughters of Count Albert IV of Tyrol, attended with reasonable succession prospects in the Tyrolean lands.

During the turmoil after the death of Emperor Frederick II, Count Meinhard, backed by his father-in-law Albert IV of Tyrol, tried to gain control over the Duchy of Carinthia but failed in an unsuccessful campaign against Duke Bernhard von Spanheim and his son Philip, the elected Archbishop of Salzburg.

Meinhard and Albert IV of Tyrol also had to pay a compensation and to renounce certain possessions including Mittersill, Virgen, Matrei and Oberdrauburg.

His son Meinhard II later also acquired the Hirschberg lands from Gebhard's heirs in 1284 and two years later even received Carinthia from the hands of the Habsburg king Rudolf I of Germany.