Ulf

Ulf was a bodyguard to Earl Haraldson. He appears in Season 1 of Vikings. He is now loyal to Earl Ragnar.

Season 1
Ulf is present in the Earls halls when he enters. Ulf silences everyone in the room. He is present during the execution of Eric Trygvasson.

Ulf helps the Earl raid Ragnar's farm, it is likely that he killed numerous farmers during the attack.

Ulf is present at Thyri's wedding to Earl Bjarni of Sveatland when Rollo talks to the Earl. After Rollo meets with Siggy in secret, Ulf is joined by seven other thugs of Earl Haraldson. They beat down Rollo with clubs, bringing him back to the Earl.