Lupus was patriarch between 940 and 948-949. He is mentioned in 942 for an agreement, which was mediated by the Venetian doge Peter Candiano III, to settle the borders with Marinus, patriarch of Grado. In 944, together with Gotfred, marquis of Istria, Lupus rushed to the help of Carinthians against Hungarians, but was harshly defeated. Lupus escaped, while Gotfred was killed. In 948 Henry I duke of Bavaria, brother to Otto I king of Germany, freed Lombardy and Friuli from Hungarians, occupied Aquileia, executed patriarch Lupus II, and appointed Engelfred, a German, to his post.