Grasulf I (died after 571) was a brother of Alboin, the first Lombard King of Italy, and possibly the first Duke of Friuli. Grasulf's son, Gisulf, is the other candidate for first Duke of Friuli. Paul the Deacon names Gisulf, but some scholars have favoured Grasulf based on a diplomatic letter which refers to him as duke. While the exact location of Grasulf's seat of power is unknown, if he did rule, the letter from Gogo is evidence that the "Friulian court" was capable of handling sophisticated imperial correspondence less than a decade after the Lombard arrival on Italian soil.