In May 1918 the Czechoslovak Legion revolted on the Trans-Siberian Railway. On June 8, the Czech Legion captured Samara, Russia, and several members of the Constituent Assembly, which had been dissolved by the Bolsheviks, organized a Committee of Members of the Constituent Assembly. On the same day an organization of underground officers was established under the supervision of the Socialist-Revolutionary Party. On June 10 a group of officers of the general staff arrived and helped organize a military structure. They created a detachment of 350 men, which had two infantry companies, a cavalry squadron and a mounted artillery detachment. General Vladimir Kappel became a chief of this military group. Kappel was a monarchist, and stated that he would fight under any banner against the Bolsheviks.