 On the afternoon of 18 March, following the government's failed attempt to seize the cannons at Montmartre, the Central Committee of the National Guard ordered the three battalions to seize the Hôtel de Ville, where they believed the government was located.They were not aware that Thiers, the government, and the military commanders were at the Ministry of Foreign Affairs, where the gates were open and there were few guards.They were also unaware that Marshal Patrice MacMahon, the future commander of the forces against the Commune, had just arrived at his home in Paris, having just been released from imprisonment in Germany.