 On Wednesday, 26 April, the guns at Trinity College and "Helga" shelled Liberty Hall, and the Trinity College guns then began firing at rebel positions, first at Boland's Mill and then in O'Connell Street.Some rebel commanders, particularly James Connolly, did not believe that the British would shell the 'second city' of the British Empire.The principal rebel positions at the GPO, the Four Courts, Jacob's Factory and Boland's Mill saw little action.