Season 1 Origins Sky Showcase , 2010 Watch now Season 2 Project Dawn Cinemax , 2011 Watch now Season 3 Vengeance Cinemax , 2012 Watch now Season 4 Shadow Warfare Cinemax , 2013 Watch now Season 5 Legacy Sky Showcase , 2015 Watch now Season 6 Retribution Sky Showcase , 2017 - 2018 Watch now Season 7 Silent War Cinemax , 2019 Watch now Season 8 Vendetta Cinemax , 2020 Watch now