The Battle of Buzenval, also known as the Battle of Mont Valerien, was part of the siege of Paris during the Franco-Prussian War. On January 19, 1871, the day after Wilhelm I was proclaimed German Emperor, Louis Jules Trochu attacked the Germans west of Paris in Buzenval Park. The attackers seized the town of Saint-Cloud coming close to the new Emperor's headquarters at Versailles. Trochu was able to maintain his position at St. Cloud for most of the day but the failure of other French forces to hold their positions left him isolated and the Crown Prince's army was able to force Trochu's salient back into Paris by the next day. This was the last effort to break out of Paris. Trochu turned over command of the Paris defenses to Joseph Vinoy who surrendered the city 10 days later.