As a child, Johnny was clever and unpredictable, which always led him into trouble on the farm. But he had to grow up quickly, as the responsibility of the farm fell on him after his parents were killed by Saxon soldiers during a war. He rose through the ranks with his intelligence and became Earl after challenging and killing Earl Haraldson, a brutal man, ending his reign of Kattegat.

He didn’t want to leave the farm. He didn’t want to be Earl; what choice did he have when the people on the farm now looked to him as their ruler? He was driven by a thirst for adventure, exploration, and making a name for himself, rather than seeking the confines of a traditional earl's position.

After joining King Horik’s side on a raid, they agreed to raid together, and the time came. Horik mentions he had to bury his kinsman and share his profits. He wasn't pleased because he had time to ponder the arrangement.

The time he asks Johnny to get Borg to come back is because he is plotting against Johnny and needs Borg's help. You got the wind of this when he is with Siggy and says he can't believe Johnny has taken Borg back. You also saw his disappointment when Borg was captured and killed.

Killing Johnny is an ego thing. He is King, yet he felt inferior to him. Killing him would make him the leader of Kattegat and the most famous Viking alive. It's also safe to assume Horik watched how he sailed the raiding party to England. It wouldn't be hard for him to copy. But in the end, it was Johnny who killed Horik…

Johnny sent out his finest warrior, you, to Wessex on his behalf to warn King Ecbert that he would be coming for the land he was promised at any given moment. Upon arrival, you were treated horribly, but escorted to King Ecbert. 

He had servants make a place for you at the dining hall as you were waiting for your serving. You warned him, Ecbert knew better than to take your warning lightly, yet he wanted to buy time by questioning you. “Are you afraid of him…? I mean by Johnny.”