They say you only get one chance to make a first impression. Well, the opening scene of Vikings Season 1 Episode 1 clearly establishes Ragnar Lothbrok (and his brother, Rollo) as tough Viking warriors... Ouch!

When Ragnar's boat was completed, a small band of Vikings made their way West. Who can forget their first attack on the helpless monks at Lindisfarne? While most of the priests were killed, Ragnar took Athelstan as his slave; they've since become BFF's.

On their second visit to England, the Vikings landed in Wessex. During the raid, Earl Haraldson's half-brother, Knut, attempted to rape Lagertha. The shieldmaiden gutted him like a fish. Of course, this caused Ragnar a world of trouble later.

Speaking of Earl Haraldson, after attempting to kill his family and burning down his home, Ragnar challenged him to a trial by combat. The fight was pretty straightforward, but then Ragnar slashed the wounded Haraldson's wrists to finish him off. Needless to say, Siggy was not pleased.

The Vikings believed they could take their possessions with them into the afterlife. One of Haraldson's slave girls agreed to be sacrificed and joined the Earl on his funeral pyre.

In a definite foreshadowing of Ragnar's fate, King Aelle of Northumbria, threw one of his generals into a snake pit after losing a battle to Ragnar and the Northmen.

Though Ragnar brought Athelstan to die at the temple at Uppsala, it was Leif that ended up sacrifcing himself for his new Earl. The sight of slaughtered humans and animals hanging upside down still sends a chill down my spine.

Rollo turned his back on his brother, which lead to the massive battle that opened Vikings Season 2. Fans thought Floki might die, but it was One-Eye who Rollo impaled and lifted above his head as Ragnar watched.

When Ragnar and King Horik raided England together in Vikings Season 2 Episode 3, one of the most disturbing scenes was when they used the priest for target practice. Ultimately, it was Athelstan who killed the man as an act of mercy.

Throughout its run, Vikings has given us some truly uncomfortable scenes. However, Athelstan's crucifixion is probably still at the top of my list. Here was a character we had grown to love, being tortured and potentially dying at the hands of the English. Luckily, King Ecbert arrived in time to have the ex-monk's life spared.

Earl Sigvard was a cruel and abusive husband. Fed up with his nasty ways, Lagertha stabbed him in the eye during dinner. It was his nephew, Einar, that dealt the death blow by beheading Sigvard. Lagertha became Earl soon afterwards.

The blood eagle was supposedly a Viking form of execution, though it's historically disputed today. When Jarl Borg invaded Kattegat and took Ragnar's lands, he was sentenced to death via Blood Eagle. Though filmed tastefully, the thought Ragnar cut into Borg's skin along the spine, cracked his rib cage open and pulled the lungs out resting them on his back like wings was horrifying.

King Horilk plotted against Ragnar throughout most of Vikings Season 2. Not only did Ragnar kill the manipulative king, but he slaughtered his entire family as well. Bjorn walked in to find a room full of dead young women and children.

Ragnar and his men easily overpowered Kwentrith's Uncle in Mercia. Though she watched Floki kill her abusive uncle, Kwentrith asked Rangar for his head as proof. She later unleashed all her anger on it by repeatedly stabbing the decapitated head and tossing it away.

Princess Kwenthrith's uncle was just the first head Vikings Season 3 Episode 2 gave us. In order to scare the bejesus out of her brother's troops, Ragnar decorated his ships with Mercian heads. It's a safe bet Kwenthrith's brother, Burgred, pooped in his pants at the sight.

When Torstein was wounded early on, it was clear the character's days were numbered. However, first he had to suffer an excruciating amputation at the hands of Floki. Torstein died bravely on Vikings Season 3 Episode 3 by charging the Hill of the Ash first, giving the Northmen a fighting chance. His place in Valhalla awaited him.

We've seen many sacrifices on HISTORY's Vikings throughout the series. However, the blood sacrifice of the bull in Vikings Season 3 Episode 3 was as unsettling a scene as any we've seen so far. Though human sacrifice by the Vikings is questionable, there's little doubt animals were sacrificed as part of their rituals and beliefs.