Vikings season 4 premiere synopsis and air date: King Ragnar hangs between betrayal and loyalty

After a great season 3, History channel's Irish-Canadian historical drama Vikings is all set to return on television with season 4 to narrate the story of king Ragnar Lothbrok. This time the popular series will return with 20 episodes.

The synopsis of season 4 as cited by TV Fanatic, reads: "It culminated with the extraordinary battle in Paris, where Ragnar seized victory from the jaws of defeat – but still returns to Kattegat dangerously ill. Thoughts of his death galvanize the forces who seek to succeed him as king, including his wife Queen Aslaug and his oldest son, Bjorn.

"Meanwhile, Lagertha continues power struggles with her calculating, former second in command, Kalf; Rollo betrays his Vikings heritage by remaining in Frankia and Floki is seized for his brutal actions to the Christian priest Athelstan."

The show narrates the Vikings lord's dilemma about his faith and his rule as a king and his difficulty in handling his family. While his former wife Lagertha emerged as a loyal ally to him, his wife Aslaug is secretly power hungry. The king is also losing faith in his eldest son Bjorn.

Season 4 is expected to bring some exciting twists in Ragnar's life with regards to his relationship with his brother Rollo and his best friend Floki as he is caught between betrayal and loyalty.

As shown in the trailer, the King of Denmark will learn the truth about Athelstan's death and will punish Floki for killing him. On the other hand, Aslaug will seek help from the Wanderer and ask him about her future as the woman ruler of Kattegat.

In season 3 of the popular historical drama, the Vikings king wins the impenetrable city of Paris after almost being defeated. Ragnar faked his death to enter Paris but keeps his family in the dark about his plan. Assuming him dead, his family will confess their deep dark secrets to him. It remains to be seen how the King of Denmark will deal with the bitter truth.

The series will introduce new character King Harold Finehair who aspires to become the King of Norway. The role will be played by Peter Franzén. He will pose the biggest threat to King Ragnar in season 4.

Vikings season 4 part one will consist of 10 episodes and will premiere on 18 February 2016. The remaining 10 episodes will air later the same year.