Easter Rising in putting the rising off for only a day, although it greatly reduced the number of Volunteers who turned out. British Naval Intelligence had been aware of the arms shipment, Casement's return, and the Easter date for the rising through radio messages between Germany and its embassy in the United States that were intercepted by the Royal Navy and deciphered in Room 40 of the Admiralty. The information was passed to the Under-Secretary for Ireland, Sir Matthew Nathan, on 17 April, but without revealing its source, and Nathan was doubtful about its accuracy. When news reached Dublin of the capture
Easter, 1916 figures who eventually led the uprising. The deaths of these revolutionary figures at the hands of the British, however, were as much a shock to Yeats as they were to ordinary Irish people at the time, who did not expect the events to take such a bad turn so soon. Yeats was working through his feelings about the revolutionary movement in this poem, and the insistent refrain that "a terrible beauty is born" turned out to be prescient, as the execution of the leaders of the Easter Rising by the British had the opposite effect to that intended. The killings