 The series was given a budget of $ 100 million ( £ 58 million ) , the largest both HBO and the BBC had ever devoted to a series . The season was filmed between March 2004 and July 2005 , at locations in or around Rome , and on a set considered " to be the biggest and most expensive ever built for television . " It was built at <unk> , where the epic films Ben @-@ <unk> ( 1959 ) and Cleopatra ( 1963 ) had been filmed . Production designer Joseph Bennett built a set that emphasized authenticity and realism rather than grandiosity . He said , 
