 The plot combines elements of life of the historic queen Boudica (featuring the Iceni tribe, combat chariots) with elements seemingly drawn from Vincenzo Bellini's opera "Norma", though that is set in Gaul.The film was budgeted at £350,000 and went over budget by £61,000.During filming in Ireland, Patrick Troughton, who was playing the part of Tristram, was offered the role of the Second Doctor in "Doctor Who".