The "Vikings" Season 4 episode 19, titled "On the Eve," spoilers suggest that the upcoming episode will see the sons of Ragnar battle against King Ecbert and Aethelwulf. The episode will decide the fate of King Ecbert. It will be interesting to see who wins the battle as Ragnar's sons are keen to avenge the death of their father.

Notably, "On the Eve" is going to be the penultimate episode of "Vikings" Season 4. It is expected that episode 19 will focus on the big battle and the season finale episode will showcase the aftermath of the violent encounter.

"The Viking army causes panic in the English countryside as King Ecbert and Aethelwulf plan the defense of the realm," the official "Vikings" Season 4 episode 19 synopsis teases.

 "The true heir to the great Ragnar Lothbrok will turn out to be a cripple," Ivar tells Bjorn.

In episode 18, the father-son duo King Ecbert and Aethelwulf (Moe Dunford) shared an emotional conversation when Aethelwulf finally asked his father if he really loves him. The father didn't give an answer.

Spoilers suggest that in the upcoming episode 19 of the "Vikings" Season 4, fans can expect to see some action-packed battle sequences. In fact, showrunner Michael Hirst has also revealed that the next episode will see some "truly awesome battle sequences." It still remains unknown as to how the father-son duo will defend their realm, what their big defense plan will be or whether or not they will be successful in implementing their plan.

"This is the time to act," King Ecbert says in the promo.

Will King King Ecbert die? To know what happens don't forget to watch "Vikings" season 4 episode 19 at 9PM ET on Jan.25 on the History Channel.