At the start of the Franco-Prussian War, Saarbrücken was the first target of the French invasion force which drove off the Prussian vanguard and occupied Alt-Saarbrücken on 2 August 1870. Oral tradition has it that 14-year-old French Prince Napoléon Eugène Louis Bonaparte fired his first cannon in this battle, an event commemorated by the "Lulustein" memorial in Alt-Saarbrücken. On 4 August 1870 the French left Saarbrücken, driven away towards Metz in the Battle of Spicheren on 6 August 1870.