 Scottish actor Kevin McKidd , who had never appeared in a television series that necessitated over twelve months of filming , was cast as Lucius Vorenus , one of the lead characters . McKidd said , " What was different about this show is you get 14 months to really get into every <unk> and <unk> of the character , in a way you don 't get a chance to explore when you do a movie or a theater play . Initially , it was a terrifying prospect . But once you got over that , you realize what a great opportunity it was . " Heller described his character as " very much a Roman of the Old School , a stoic man devoted to duty and religion and the legion . " Ray Stevenson played Titus Pullo , a soldier who befriends Vorenus . McKidd said that " they 're kind of thrown together by fate , by chance , but somewhere along the line they start to stick ... [ They ] keep finding themselves accidentally at the epicenter of tumultuous events and immense change , so they 're kind of <unk> to each other . " 
