Just before the prisoners are captured, we see a carriage with French soldiers driving through the uncompleted Arc de Triomphe, which still has wooden scaffolding on it. As the Arc de Triomphe was commissioned by Napoleon Bonaparte in 1806 after he had defeated Austria and Russia at Austerlitz, this would indicate that the cartoon is set just after the War of the Fifth Coalition, when Napoleon next invaded Austria, in 1809.
A reporter once asked John Lennon, "How did you find America?" Lennon replied, "Turned left at Greenland."