He was the son of Count
Engelbert III of Gorizia and his wife
Matilda, daughter of
Berthold I of Istria and sister of the powerful
Andechs duke
Berthold IV of Merania. Through his mother, Meinhard inherited the County of
Mittelburg in central
Istria. 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. Meinhard strongly supported the
Hohenstaufen emperor
Frederick II in his fierce conflict with
Pope Innocent IV and in return was appointed Imperial governor of the
Duchy of Styria and the
March of Carniola after the last
Babenberg duke
Frederick the Warlike had died without heirs in 1246. From 1250 onwards also governor in the princeless
Duchy of Austria, Meinhard facing the fall of the Hohenstaufen dynasty did not prevail: his rule in Carniola was challenged by the
Carinthian ducal
House of Sponheim, and in Austria and Styria he was expelled by the
Bohemian prince
Ottokar II Přemysl in 1251. 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. On 8 September 1252, he was finally defeated and arrested at
Greifenburg. According to the Peace of
Lieserhofen, concluded on 27 December 1252, he had to give his sons
Meinhard IV and
Albert to Archbishop Philip as hostages. Both were imprisoned at
Hohenwerfen Castle in Salzburg and not released until 1258. Meinhard and Albert IV of Tyrol also had to pay a compensation and to renounce certain possessions including
Mittersill,
Virgen,
Matrei and
Oberdrauburg. Upon the death of Count Albert IV of Tyrol in 1253, Meinhard and his brother-in-law, Count Gebhard of
Hirschberg, split Tyrol, of which Meinhard took the southern part with
Meran, in constant quarrels with the
Trento bishops. 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. Meinhard I died in 1258 and is buried at
Tirol Castle. ==Marriage and children==