The cast of "Vikings," a successful drama on History, has been acclaimed for its ability to create credible plot arcs that span decades on screen. Fans have become so attached to characters like Ragnar Lothbrok (Travis Fimmel), Lagertha (Kathryn Winnick), and Floki (Gustaf Skarsgard) that the actors and actresses will be forever associated with their roles on "Vikings," especially those who have played characters who have been with the show since its premiere in 2013.