Britannia Main cast, played by Ian McDiarmid Episode 1x01: Episode 1 (Jan 18, 2018) Episode 1x02: Episode 2 (Jan 18, 2018) Episode 1x03: Episode 3 (Jan 18, 2018) Episode 1x04: Episode 4 (Jan 18, 2018) Episode 1x07: Episode 7 (Jan 18, 2018)