Dukes Gisulf II of Friuli and Gaidoald of Trent had been at odds with King Agilulf until they made peace in 602 or 603.
Gisulf had also allied with the Avars to make war on Istria.
Gisulf is involved in the local church.
The bishops of "the schismatics of Istria and Venetia," as Paul the Deacon calls them, had fled to the protection of Gisulf.
Gisulf had also taken part in the confirmation of the succession of Candidianus to the patriarchate of Aquileia in 606.
The most significant event of his reign occurs probably in 611.
When the Avars invade Italy, Gisulf's territory is the first they pass through.
Gisulf summons a large army and goes to meet them.
The Avars are a larger force, however, and they soon overwhelm the Lombards.
Gisulf dies in battle, and his duchy is overrun.
He leaves four sons and four daughters by his wife Romilda (or Ramhilde).
His elder two sons, Tasso and Kakko, along with their younger brothers Radoald, and Grimoald, escapes the Avars and evade capture, successfully setting themselves up as Gisulf's successors.
Of two of Gisulf’s daughters, Appa and Geila (or Gaila), Paul the Deacon says that one married the King of the Alemanni (uncertain) and another the Prince of the Bavarians, probably Garibald II of Bavaria, but he does not identify who married whom.
