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
St. Enda's School radical politics also made even some moderate supporters question what their children might be exposed to, and some, notably Eoin MacNeill, removed their children from Pearse's influence. As it turned out, a large number of St. Enda's pupils did join the Fianna Éireann, and even the IRB, fifteen of whom later took part in the Easter Rising in 1916. Following the execution of the Pearse brothers after the rising, their mother reopened St. Enda's back at Cullenwood House, which the closure of St. Ita's had vacated. Frank Burke, an ex-pupil who had served in the Rising, was headmaster. The school