He backed the efforts by Grand Master Hermann von Salza to reach a reconciliation between Emperor Frederick II and Pope Gregory IX and sealed a 1230 peace agreement in the church of San Germano.

Moreover, the Salzburg archbishops were able to strengthen their position by establishing the suffragan dioceses of Seckau and Lavant in 1218 and 1225 respectively, while the duke picked a long-time quarrel with Count Meinhard III of Gorizia around the small Greifenburg estates.

In turn, Bernhard entrenched a ducal centre of force comprising the city triangle of Sankt Veit, where he established a mint in 1205, Völkermarkt, and Klagenfurt, the later Carinthian capital that he had transferred to its present location in 1246.

Duke Bernhard's exalted rank corresponds to his wedding with Judith, daughter of the Přemyslid King Ottokar I of Bohemia and the Árpád princess Constance of Hungary, in 1213.

His younger brother Philip was claimant to the estates of Carinthia and Carniola, he nevertheless could not prevail against his first cousin King Ottokar II of Bohemia, who in 1268 had signed an inheritance treaty with late Duke Ulrich.