Asterix in Britain(1986)

Original title: Astérix chez les Bretons

One little ancient British village still holds out against the Roman invaders. Asterix and Obelix are invited to help. They must face fog, rain, warm beer and boiled boar with mint sauce, but they soon have Governor Encyclopaedius Britannicus's Romans declining and falling. Until a wild race for a barrel of magic potion lands them in the drink.