Easter Monday, 24 April
Most of those who took part in the Rising assembled at Liberty Hall and proceeded from there to their allotted positions, most of which were occupied by noon. Following the occupation of the GPO, Pearse proclaimed the establishment of the Irish Republic. As Commandant General of the Dublin Brigade of the Army of the Irish Republic, in theory James Connolly directed the military operations of all the positions held in the name of the Irish Republic; in practice, however, due to his inability to provide worthwhile reinforcements or armaments, the commandants of the outlying positions generally had to rely on their own devices. In the course of Monday afternoon and evening the British organised a hurried response and engaged most of the positions occupied by the insurgents. City Hall came under intense attack and the officer in charge, Captain Seán Connolly, was shot dead. The few remaining members of the garrison surrendered later that night. Commandant Ceannt's position at the South Dublin Union also came under intense pressure but the garrison repulsed the attacks. An outpost set up by Commandant Mallin in J.&T. Davy's public house at the junction of South Richmond Street and Charlemont Mall had to abandoned within a matter of hours in the face of intense fire.