Horrible Histories: The Movie - Rotten Romans (2019)

Atti, a witty Roman teenager is forced to join the army until one of his schemes upsets Emperor Nero. As a punishment, he is sent to the cold wet Britain on the fringe of the Roman Empire. He is captures by Orla, a feisty Celt who eventually comes to understand his good nature. Atti is brought back to the regiment where he discovers that the army is preparing for a battle to crush the Celts at the Battle of Watling Street. He must now use his wits to save the day and prevent a battle where he is pitted against Orla and her tribe.