Violence is present in most episodes.
The worst scene is the first Blood Eagle execution. Although you barely see anything of the act, the sound effects perfectly describe what is happening. The second Blood Eagle execution is extremely graphic and disgusting but it lacks the tension from the first one.
In many scenes you only see the bloody, gory aftermath.
A hand is chopped in half. Graphically shown.
There are frequent moderately violent scenes and occasional extreme violence, for example a man's lungs are cut out of his back and placed on his shoulders in a punishment ritual.
A man is tied to a pole. A woman approaches him, pulls a knife, and cuts off his penis. This is not shown but it is made clear what is going on.
There are a few scenes in which peoples heads are smashed, showing brains, twice with hammers, and one where only the aftermath is seen
Nothings to say about Violence & gore because the show describes how Vikings live.
Gratuitous and realistic. Bloody battles show close-up sword fights, stabbings, and agonizing death. Corporal punishment is carried out by beheading (in one scene, the victim's head is held up after death to the crowd's cheers) and a stoning gauntlet, among other varieties. Sexual assault and physical attacks are a constant threat to women and children as well.
During battles, raids, and assassinations throughout the series, people are beheaded (the bloody aftermath is shown), slashed, stabbed and shot with arrows, sometimes with bloody results.