Walk to Canossa
Berthold remained the only Carinthian duke from the Zähringen dynasty. Both in Carinthia and Verona, like his Ezzonid predecessor, he was considered a foreign ruler and was never really accepted by the local nobles. According to the contemporary chronicler Lambert of Hersfeld, he was even temporarily declared deposed in 1072/73. Moreover, Berthold fell out with King Henry IV during the fierce Investiture Controversy when, together with Duke Welf I of Bavaria, he supported the election of his former rival Rudolf of Rheinfelden as antiking, after King Henry's Walk to Canossa in 1077. In turn, the king convened the Imperial Diet at Ulm, where he seized the duchy and gave Carinthia to Liutold of Eppenstein, whose grandfather Adalbero had held it until 1035.