A large part of the Irish Republican Army opposed the Treaty and in March 1922 voted at an Army Convention to reject the authority of the Dail, Collins' GHQ and to elect their own Executive. Anti-Treaty IRA units began to seize buildings and take other guerrilla actions against the Provisional Government. On 14 April 1922, a group of 200 anti-Treaty IRA men occupied the Four Courts in Dublin under Rory O'Connor, a hero of the War of Independence. The Four Courts was the centre of the Irish courts system, originally under the British and then the Free State. Collins was charged by his Free State colleagues with putting down these insurgents, however, he resisted firing on former comrades and staved off a shooting war throughout this period.