Watch two new trailers for 'Vikings' The world of Vikings is sailing into a dark season 3 with two new promos. 'Vikings' Season 3 Spoilers: CGI For Massive Paris Battle, What Is Ragnar's Plan? The History Channel show will return in February, and fans of Ragnar (Travis Fimmel) and his warriors can get their first look at the upcoming season since the July Comic-Con teaser.